{"id":657,"date":"2026-10-02T13:17:45","date_gmt":"2026-10-02T11:17:45","guid":{"rendered":"https:\/\/www.valfonta.com\/producto\/excess-pressure-valve-model-prv55\/"},"modified":"2026-10-22T09:22:35","modified_gmt":"2026-10-22T07:22:35","slug":"excess-pressure-valve-model-prv55","status":"publish","type":"product","link":"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/","title":{"rendered":"PRV55 excess pressure valve"},"content":{"rendered":"<div class=\"wp-block-group vf-raiz vf-pl-ficha-producto is-layout-flow wp-block-group-is-layout-flow\"><nav class=\"wp-block-group vf-breadcrumbs vfa-aria-label--Breadcrumbs is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><a href=\"\/en\/\">Home<\/a><span class=\"vf-sep\" aria-hidden=\"true\">\u203a<\/span><a href=\"https:\/\/www.valfonta.com\/en\/pressure-relief-valve\/\">Pressure relief valves<\/a><span class=\"vf-sep\" aria-hidden=\"true\">\u203a<\/span><span aria-current=\"page\">PRV55 excess pressure valve<\/span><\/p><\/nav><article class=\"wp-block-group vf-pdp vfd-model--PRV55 is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-pdp-hero is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-pdp-title is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-pdp-eyebrow wp-block-paragraph\">Excess pressure valve \u00b7 Diaphragm actuator<\/p><h1 class=\"wp-block-heading\">PRV55 excess pressure valve<\/h1><\/div><div class=\"wp-block-group vf-pdp-media is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><span class=\"vf-pdp-badge\">From 10 mbar<\/span><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV45-55-700x700-1.jpg\" alt=\"PRV55 excess pressure valve with diaphragm actuator and 316L stainless steel body\" class=\"wp-image-191\" width=\"700\" height=\"700\" fetchpriority=\"high\"><\/p><\/div><div class=\"wp-block-group vf-pdp-body is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-lead wp-block-paragraph\">Self-regulating, direct-acting excess pressure valve with a diaphragm actuator and body and internals in 316L stainless steel. It discharges the excess when the upstream pressure exceeds the set pressure, adjustable from 0.01 barg, on gases, liquids, and steam up to 150 \u00b0C.<\/p><ul class=\"vf-pdp-keys wp-block-list\"><li><span>Sizes<\/span><b>DN15 to DN25<\/b><\/li><li><span>Pressure rating<\/span><b>PN25<\/b><\/li><li><span>Set pressure range<\/span><b>0.01 to 8 barg <small>depending on actuator<\/small><\/b><\/li><li><span>Inlet pressure<\/span><b>up to 16 barg<\/b><\/li><li><span>Temperature<\/span><b>\u221210 to 150 \u00b0C <small>with Viton gaskets<\/small><\/b><\/li><li><span>Kv<\/span><b>2 to 3.5 m\u00b3\/h<\/b><\/li><\/ul><div class=\"wp-block-group vf-pdp-cta is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><a class=\"vf-btn vf-btn--pri\" href=\"#solicitar\">Request a quote<\/a><a class=\"vf-btn vf-btn--sec\" href=\"\/wp-content\/uploads\/2026\/10\/PRV55-16B-ENG.pdf\" target=\"_blank\" rel=\"noopener\">Download datasheet <small>PDF<\/small><\/a><\/p><\/div><p class=\"vf-pdp-contact wp-block-paragraph\">Questions about set pressure or sizing? Call <a href=\"tel:+34933720888\">933 720 888<\/a> or email <a href=\"mailto:valfonta@valfonta.com\">valfonta@valfonta.com<\/a>.<\/p><\/div><\/div><ul class=\"vf-pdp-trust wp-block-list\"><li>In-house design and manufacturing in Badalona<\/li><li>ATEX II 2 GD marking for zones 1 and 21<\/li><li>All valves are supplied degreased<\/li><li>Genuine spare parts available<\/li><\/ul><nav class=\"wp-block-group vf-pdp-nav vfa-aria-label--Datasheet%20contents is-layout-flow wp-block-group-is-layout-flow\"><ul class=\"wp-block-list\"><li><a href=\"#aplicaciones\">Applications<\/a><\/li><li><a href=\"#especificaciones\">Specifications<\/a><\/li><li><a href=\"#funcionamiento\">Operation<\/a><\/li><li><a href=\"#instalacion\">Installation<\/a><\/li><li><a href=\"#documentacion\">Documentation<\/a><\/li><li><a href=\"#comparar\">Compare<\/a><\/li><li><a href=\"#preguntas\">FAQ<\/a><\/li><li><a href=\"#solicitar\">Request a quote<\/a><\/li><\/ul><\/nav><section id=\"aplicaciones\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-pdp-two is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">What the PRV55 is used for<\/h2><p class=\"wp-block-paragraph\">The <strong>PRV55<\/strong> is a self-regulating <a href=\"https:\/\/www.valfonta.com\/en\/pressure-relief-valve\/\">excess pressure valve<\/a>: it needs no auxiliary power. The upstream pressure reaches a <strong>diaphragm<\/strong>, and when it exceeds the set value, the valve opens proportionally and relieves the excess.<\/p><p class=\"wp-block-paragraph\">The diaphragm allows set pressures <strong>from 10 mbar<\/strong>; the rest of the range starts at 0.5 barg. It is especially designed for gases, although it also works with liquids and steam. More detail in our article on <a href=\"https:\/\/www.valfonta.com\/en\/blog\/self-regulating-excess-pressure-valves\/\">excess pressure valves<\/a>.<\/p><ul class=\"vf-pdp-apps wp-block-list\"><li><b>Low-pressure gases<\/b><span>Compressed air, nitrogen, and inert gases with set pressures from 0.01 barg.<\/span><\/li><li><b>Steam plants<\/b><span>Steam networks and heat exchangers, with condensate pot.<\/span><\/li><li><b>Chemical laboratories<\/b><span>Stable pressure in gas and liquid circuits.<\/span><\/li><li><b>Fuel oil and sprinklers<\/b><span>Group 1 and 2 liquids, such as fuel oil or water.<\/span><\/li><\/ul><\/div><aside class=\"wp-block-group vf-pdp-fit is-layout-flow wp-block-group-is-layout-flow\"><h3 class=\"wp-block-heading\">Choose the PRV55 if\u2026<\/h3><ul class=\"vf-si wp-block-list\"><li>You need very low set pressures, from 10 mbar, up to 8 barg.<\/li><li>You work with Group 1 and 2 gases, liquids, or steam, up to 150 \u00b0C.<\/li><li>You need small sizes, from DN15 to DN25, with a 316L stainless steel body.<\/li><li>You are looking for a self-regulating valve, with no air or electricity.<\/li><\/ul><h3 class=\"wp-block-heading\">Choose another model if\u2026<\/h3><ul class=\"vf-no wp-block-list\"><li>Your set pressure is above 8 barg: the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv54\/\">PRV54<\/a> reaches 12 barg, the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s2\/\">S2<\/a> 10, and the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-relief-valve-s3\/\">S3<\/a> 20.<\/li><li>The temperature exceeds 150 \u00b0C: the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv54\/\">PRV54<\/a> handles 210 \u00b0C, and the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s1\/\">S1<\/a> and the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-relief-valve-s3\/\">S3<\/a>, 220 \u00b0C.<\/li><li>You need more than DN25: the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s1\/\">S1<\/a> and the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-relief-valve-s3\/\">S3<\/a> go up to DN150, and the <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s2\/\">S2<\/a> up to DN100.<\/li><\/ul><\/aside><\/div><\/section><section id=\"especificaciones\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">PRV55 technical specifications<\/h2><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-tbl\"><table><tbody><tr><th scope=\"row\">Type<\/th><td>Self-regulating, direct-acting, piston-balanced excess pressure valve with diaphragm actuator<\/td><\/tr><tr><th scope=\"row\">Sizes<\/th><td>DN15 (\u00bd\u2033), DN20 (\u00be\u2033), and DN25 (1\u2033)<\/td><\/tr><tr><th scope=\"row\">Connections<\/th><td>BSP or NPT thread \u00b7 EN flanges \u00b7 ANSI CL150 flanges \u00b7 Clamp on request<\/td><\/tr><tr><th scope=\"row\">Pressure rating<\/th><td>PN25<\/td><\/tr><tr><th scope=\"row\">Maximum inlet pressure<\/th><td>16 barg<\/td><\/tr><tr><th scope=\"row\">Set pressure range<\/th><td>0.01 to 8 barg, depending on actuator size and spring<\/td><\/tr><tr><th scope=\"row\">Kv coefficient<\/th><td>2 m\u00b3\/h (DN15) \u00b7 2.5 m\u00b3\/h (DN20) \u00b7 3.5 m\u00b3\/h (DN25). Special Kv on request<\/td><\/tr><tr><th scope=\"row\">Temperature<\/th><td>\u221210 to +150 \u00b0C (with Viton gaskets)<\/td><\/tr><tr><th scope=\"row\">Fluids<\/th><td>Group 1 and 2 liquids and gases: steam, compressed air, fuel oil, water, nitrogen, inert gases<\/td><\/tr><tr><th scope=\"row\">Materials<\/th><td>Body and internals in AISI 316L stainless steel. EPDM or EPDM+PTFE diaphragm. Steel sheet actuator with epoxy paint<\/td><\/tr><tr><th scope=\"row\">Pressure sensing point<\/th><td>Internal or external. External required with steam and with liquids above 125 \u00b0C<\/td><\/tr><tr><th scope=\"row\">Mounting position<\/th><td>Horizontal pipe. Actuator facing down with any fluid and always with steam; facing up only with gases and liquids up to 80 \u00b0C<\/td><\/tr><tr><th scope=\"row\">Pressure Equipment Directive<\/th><td>PED 2014\/68\/EU, Article 4.3: CE marking not required (Group 1 and 2 fluids)<\/td><\/tr><tr><th scope=\"row\">ATEX<\/th><td>II 2 GD c IIC Tx \/ c IIIC Tx\u00baC \u00b7 certificate LOM 14.034 U<\/td><\/tr><tr><th scope=\"row\">On request<\/th><td>RG10 bronze body \u00b7 stainless steel actuator \u00b7 special gaskets \u00b7 special Kv<\/td><\/tr><\/tbody><\/table><\/figure><\/div><h3 class=\"wp-block-heading\">Dimensions and weight<\/h3><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-tbl vf-tbl--grid\"><table><thead><tr><th scope=\"col\"><\/th><th scope=\"col\">\u00bd\u2033 threaded<\/th><th scope=\"col\">\u00be\u2033 threaded<\/th><th scope=\"col\">1\u2033 threaded<\/th><th scope=\"col\">DN15 EN<\/th><th scope=\"col\">DN20 EN<\/th><th scope=\"col\">DN25 EN<\/th><th scope=\"col\">DN15 ANSI<\/th><th scope=\"col\">DN20 ANSI<\/th><th scope=\"col\">DN25 ANSI<\/th><\/tr><\/thead><tbody><tr><th scope=\"row\">Kv (m\u00b3\/h)<\/th><td>2<\/td><td>2,5<\/td><td>3,5<\/td><td>2<\/td><td>2,5<\/td><td>3,5<\/td><td>2<\/td><td>2,5<\/td><td>3,5<\/td><\/tr><tr><th scope=\"row\">Length A \/ AA<\/th><td>108<\/td><td>108<\/td><td>108<\/td><td>130<\/td><td>150<\/td><td>160<\/td><td>184<\/td><td>184<\/td><td>184<\/td><\/tr><tr><th scope=\"row\">Height H1<\/th><td>258<\/td><td>258<\/td><td>258<\/td><td>258<\/td><td>258<\/td><td>258<\/td><td>258<\/td><td>258<\/td><td>258<\/td><\/tr><tr><th scope=\"row\">Height H2<\/th><td>320<\/td><td>320<\/td><td>320<\/td><td>320<\/td><td>320<\/td><td>320<\/td><td>320<\/td><td>320<\/td><td>320<\/td><\/tr><tr><th scope=\"row\">Flange \u00d8 D1<\/th><td>\u2013<\/td><td>\u2013<\/td><td>\u2013<\/td><td>95<\/td><td>105<\/td><td>115<\/td><td>89<\/td><td>98<\/td><td>108<\/td><\/tr><tr><th scope=\"row\">Weight (kg)<\/th><td>2,5<\/td><td>2,5<\/td><td>2,5<\/td><td>5<\/td><td>5<\/td><td>5<\/td><td>5<\/td><td>5<\/td><td>5<\/td><\/tr><\/tbody><\/table><\/figure><\/div><p class=\"vf-note wp-block-paragraph\">Dimensions in millimeters. The actuator diameter (D) depends on the set pressure range. The dimensioned drawings are in the PDF datasheet.<\/p><h3 class=\"wp-block-heading\">Set pressure range by actuator<\/h3><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-tbl vf-tbl--grid\"><table><thead><tr><th scope=\"col\">Actuator \u00d8 D (mm)<\/th><th scope=\"col\">Set pressure range<\/th><\/tr><\/thead><tbody><tr><th scope=\"row\">295<\/th><td>10 \u2013 200 mbar<\/td><\/tr><tr><th scope=\"row\">230<\/th><td>100 \u2013 1,000 mbar<\/td><\/tr><tr><th scope=\"row\">230<\/th><td>0.5 \u2013 2 barg<\/td><\/tr><tr><th scope=\"row\">175<\/th><td>1 \u2013 4 barg<\/td><\/tr><tr><th scope=\"row\">175<\/th><td>3 \u2013 8 barg<\/td><\/tr><tr><th scope=\"row\">350<\/th><td>On request<\/td><\/tr><\/tbody><\/table><\/figure><\/div><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Exploded view and materials (33 parts)<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-tbl vf-tbl--grid\"><table><thead><tr><th scope=\"col\">No.<\/th><th scope=\"col\">Part<\/th><th scope=\"col\">Material<\/th><\/tr><\/thead><tbody><tr><th scope=\"row\">1<\/th><td>Body<\/td><td>Stainless steel AISI 316L<\/td><\/tr><tr><th scope=\"row\">2<\/th><td>Sealing screw<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">3<\/th><td>Seat<\/td><td>Graphite-filled PTFE<\/td><\/tr><tr><th scope=\"row\">4<\/th><td>Gasket<\/td><td>PTFE<\/td><\/tr><tr><th scope=\"row\">5<\/th><td>Seat<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">6<\/th><td>Gasket<\/td><td>PTFE<\/td><\/tr><tr><th scope=\"row\">7<\/th><td>Valve cover<\/td><td>Steel 1.1141<\/td><\/tr><tr><th scope=\"row\">8<\/th><td>Gasket<\/td><td>PTFE<\/td><\/tr><tr><th scope=\"row\">9<\/th><td>Upper actuator<\/td><td>Steel sheet 1.0035 with epoxy paint<\/td><\/tr><tr><th scope=\"row\">10<\/th><td>Lower actuator<\/td><td>Steel sheet 1.0035 with epoxy paint<\/td><\/tr><tr><th scope=\"row\">11<\/th><td>Stem<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">12<\/th><td>Bushing guide<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">13<\/th><td>Stem guide<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">14<\/th><td>Allen screw<\/td><td>Stainless steel A2-70<\/td><\/tr><tr><th scope=\"row\">15<\/th><td>Gasket<\/td><td>Graphite-filled PTFE<\/td><\/tr><tr><th scope=\"row\">17<\/th><td>Seat holder<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">18<\/th><td>Seat guide<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">21<\/th><td>Bottom cover<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">22<\/th><td>Gasket<\/td><td>Viton<\/td><\/tr><tr><th scope=\"row\">23<\/th><td>Nut<\/td><td>Stainless steel A2<\/td><\/tr><tr><th scope=\"row\">24<\/th><td>M8 screw<\/td><td>Stainless steel A2<\/td><\/tr><tr><th scope=\"row\">25<\/th><td>KM-6 nut<\/td><td>Steel<\/td><\/tr><tr><th scope=\"row\">26<\/th><td>O-ring<\/td><td>NBR \/ Viton<\/td><\/tr><tr><th scope=\"row\">27<\/th><td>Spring support<\/td><td>Galvanized steel sheet 1.0035<\/td><\/tr><tr><th scope=\"row\">28<\/th><td>Adjusting spring<\/td><td>Steel 52SiCrNi5<\/td><\/tr><tr><th scope=\"row\">29<\/th><td>Spring cap<\/td><td>Steel 1.1191 with epoxy paint<\/td><\/tr><tr><th scope=\"row\">30<\/th><td>Adjusting screw<\/td><td>Galvanized steel 1.1191<\/td><\/tr><tr><th scope=\"row\">31<\/th><td>Adjusting nut<\/td><td>Galvanized steel 1.1191<\/td><\/tr><tr><th scope=\"row\">32<\/th><td>Spring guide<\/td><td>Galvanized steel 1.1191<\/td><\/tr><tr><th scope=\"row\">33<\/th><td>Screw<\/td><td>Stainless steel A2-70<\/td><\/tr><tr><th scope=\"row\">34<\/th><td>Nut<\/td><td>Stainless steel A2-70<\/td><\/tr><tr><th scope=\"row\">35<\/th><td>Lower diaphragm support<\/td><td>Stainless steel 316L<\/td><\/tr><tr><th scope=\"row\">36<\/th><td>Diaphragm<\/td><td>EPDM \/ EPDM+PTFE<\/td><\/tr><\/tbody><\/table><\/figure><\/div><\/div><\/details><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Recommended spare parts<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-tbl vf-tbl--grid\"><table><thead><tr><th scope=\"col\">Reference<\/th><th scope=\"col\">Description<\/th><th scope=\"col\">Parts<\/th><\/tr><\/thead><tbody><tr><th scope=\"row\">PRV55.SP1<\/th><td>Seat and balancing system kit<\/td><td>2, 3, 11, 12, 15, and 17<\/td><\/tr><tr><th scope=\"row\">PRV55.SP2<\/th><td>Gaskets<\/td><td>6 and 22<\/td><\/tr><tr><th scope=\"row\">PRV55.SP3<\/th><td>Springs<\/td><td>See the manual<\/td><\/tr><tr><th scope=\"row\">PRV55.SP4<\/th><td>EPDM diaphragm and O-rings<\/td><td>26 and 36<\/td><\/tr><tr><th scope=\"row\">PRV55.SP4<\/th><td>EPDM diaphragm, PTFE diaphragm, and O-rings<\/td><td>26, 36, and 36b<\/td><\/tr><\/tbody><\/table><\/figure><\/div><\/div><\/details><\/section><section id=\"funcionamiento\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">How the PRV55 works<\/h2><p class=\"wp-block-paragraph\">The PRV55 works on a balance between the adjusting spring and the inlet pressure acting on the diaphragm, with no air or electricity.<\/p><ol class=\"vf-steps wp-block-list\"><li><b>Closed without pressure.<\/b> As long as the inlet pressure has not reached the set pressure, the adjusting spring (28) keeps the valve closed. The piston balances the pressure acting on the seat.<\/li><li><b>Sensing at the diaphragm.<\/b> The upstream pressure reaches the diaphragm through the external control line or, optionally, through internal sensing.<\/li><li><b>Proportional opening.<\/b> When that pressure exceeds the set point, the valve opens in proportion to the pressure rise and discharges the excess. If it drops, the spring closes the valve again.<\/li><\/ol><\/section><section id=\"instalacion\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">PRV55 installation<\/h2><p class=\"wp-block-paragraph\">The typical installation of the PRV55 is on a branch of the main line, discharging to recirculation.<\/p><div class=\"wp-block-group vf-diagram vf-s-7307c0 vf-t-figure is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-svgw is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><svg viewbox=\"0 0 900 240\" role=\"img\" aria-label=\"Installation diagram of a pressure relief or excess pressure valve on a branch line\"><path d=\"M20 90 H880\" stroke=\"#9aa0a6\" stroke-width=\"6\" fill=\"none\"><\/path><path d=\"M865 90 l14 0 -10 -7 m10 7 -10 7\" stroke=\"#1e2123\" stroke-width=\"3\" fill=\"none\"><\/path><rect x=\"60\" y=\"62\" width=\"90\" height=\"56\" rx=\"4\" fill=\"#fff\" stroke=\"#1e2123\" stroke-width=\"2\"><\/rect><circle cx=\"105\" cy=\"90\" r=\"16\" fill=\"none\" stroke=\"#1e2123\" stroke-width=\"2\"><\/circle><path d=\"M97 90 l18 0\" stroke=\"#1e2123\" stroke-width=\"2\"><\/path><path d=\"M420 90 V150\" stroke=\"#9aa0a6\" stroke-width=\"5\"><\/path><rect x=\"385\" y=\"150\" width=\"70\" height=\"46\" rx=\"4\" fill=\"#fdecf1\" stroke=\"#e6305d\" stroke-width=\"2\"><\/rect><path d=\"M420 160 v24 m-7 -8 7 8 7 -8\" stroke=\"#e6305d\" stroke-width=\"2.5\" fill=\"none\"><\/path><path d=\"M455 173 H640 V215\" stroke=\"#9aa0a6\" stroke-width=\"5\" fill=\"none\"><\/path><path d=\"M632 205 l8 12 8 -12\" stroke=\"#1e2123\" stroke-width=\"2.5\" fill=\"none\"><\/path><g><circle cx=\"300\" cy=\"51\" r=\"13\" fill=\"#fff\" stroke=\"#1e2123\" stroke-width=\"2\"><\/circle><line x1=\"300\" y1=\"64\" x2=\"300\" y2=\"90\" stroke=\"#1e2123\" stroke-width=\"2\"><\/line><line x1=\"300\" y1=\"51\" x2=\"307\" y2=\"44\" stroke=\"#e6305d\" stroke-width=\"2\"><\/line><\/g><rect x=\"720\" y=\"65\" width=\"110\" height=\"50\" rx=\"4\" fill=\"#fff\" stroke=\"#1e2123\" stroke-width=\"2\"><\/rect><circle cx=\"105\" cy=\"138\" r=\"11\" fill=\"#1e2123\"><\/circle><text x=\"105\" y=\"142\" font-size=\"12\" font-weight=\"700\" fill=\"#fff\" text-anchor=\"middle\" font-family=\"Montserrat,Arial\">1<\/text><circle cx=\"324\" cy=\"38\" r=\"11\" fill=\"#1e2123\"><\/circle><text x=\"324\" y=\"42\" font-size=\"12\" font-weight=\"700\" fill=\"#fff\" text-anchor=\"middle\" font-family=\"Montserrat,Arial\">2<\/text><circle cx=\"420\" cy=\"218\" r=\"11\" fill=\"#e6305d\"><\/circle><text x=\"420\" y=\"222\" font-size=\"12\" font-weight=\"700\" fill=\"#fff\" text-anchor=\"middle\" font-family=\"Montserrat,Arial\">3<\/text><circle cx=\"640\" cy=\"232\" r=\"11\" fill=\"#1e2123\"><\/circle><text x=\"640\" y=\"236\" font-size=\"12\" font-weight=\"700\" fill=\"#fff\" text-anchor=\"middle\" font-family=\"Montserrat,Arial\">4<\/text><circle cx=\"775\" cy=\"136\" r=\"11\" fill=\"#1e2123\"><\/circle><text x=\"775\" y=\"140\" font-size=\"12\" font-weight=\"700\" fill=\"#fff\" text-anchor=\"middle\" font-family=\"Montserrat,Arial\">5<\/text><\/svg><\/p><\/div><div class=\"wp-block-group vf-t-figcaption is-layout-flow wp-block-group-is-layout-flow\"><ol class=\"wp-block-list\"><li>Pump or equipment that generates the pressure<\/li><li>Inlet pressure gauge<\/li><li>PRV55 excess pressure valve, with isolation valve and strainer upstream<\/li><li>Discharge to recirculation or tank<\/li><li>Point of use or protected equipment<\/li><\/ol><\/div><\/div><h3 class=\"wp-block-heading\">Installation and start-up<\/h3><ol class=\"vf-steps wp-block-list\"><li><b>Clean the pipe<\/b> before installing the valve: any particle can damage the seat.<\/li><li><b>Install a strainer<\/b> upstream to protect the seat and the diaphragm, with room to clean it.<\/li><li><b>Install the valve in a horizontal pipe<\/b>, following the arrow on the body. The actuator faces down (always with steam) or, with gases and liquids up to 80 \u00b0C, up; never horizontal.<\/li><li><b>Connect the external control line<\/b> with steam and with liquids above 125 \u00b0C (also recommended below that; not needed with gases): 10 \u00d7 1 mm tubing to the main pipe, at least 1 m from the valve. If the pressure fluctuates, add a needle valve.<\/li><li><b>Install the condensate pot<\/b> with steam and with liquids above 120 \u00b0C, at the highest point of the pipe, and fill it with water until it overflows before start-up.<\/li><li><b>Support the pipe, not the valve:<\/b> supports close to the flanges, never on the valve or the actuator. With steam, slope the pipe to drain the condensate.<\/li><li><b>Start up slowly:<\/b> open the isolation valves gradually to avoid water hammer.<\/li><li><b>Adjust the set pressure<\/b> with the adjusting screw. Compressing the spring raises the set pressure; releasing it lowers it. Check the value on the inlet pressure gauge.<\/li><\/ol><p class=\"wp-block-paragraph\">The valve must be installed by qualified personnel and must never exceed the operating temperature for which it was sized. In ATEX zones, the valve must be equipotentially bonded to the installation. See also our guide on relief valve set pressure.<\/p><\/section><section id=\"documentacion\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">PRV55 technical documentation<\/h2><div class=\"wp-block-group vf-docs is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-doc vf-amb-enllac is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i>PDF<\/i><\/p><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><b>PRV55 datasheet (in English)<\/b><span>PDF \u00b7 5 pages \u00b7 features, exploded view, installation, and dimensions<\/span><\/p><\/div><p class=\"vf-enllac wp-block-paragraph\"><a class=\"vf-enllac-estirat\" href=\"\/wp-content\/uploads\/2026\/10\/PRV55-16B-ENG.pdf\" aria-label=\"PDF PRV55 datasheet (in English) PDF \u00b7 5 pages \u00b7 features, exploded view, installation, and dimensions\" target=\"_blank\" rel=\"noopener\"><\/a><\/p><\/div><div class=\"wp-block-group vf-doc vf-amb-enllac is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i>PDF<\/i><\/p><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><b>Operation and installation manual (in English)<\/b><span>PDF \u00b7 13 pages \u00b7 installation, ATEX, spare parts, disassembly, and receiving<\/span><\/p><\/div><p class=\"vf-enllac wp-block-paragraph\"><a class=\"vf-enllac-estirat\" href=\"\/wp-content\/uploads\/2026\/10\/Manual-PRV55-16B-ENG.pdf\" aria-label=\"PDF Operation and installation manual (in English) PDF \u00b7 13 pages \u00b7 installation, ATEX, spare parts, disassembly, and receiving\" target=\"_blank\" rel=\"noopener\"><\/a><\/p><\/div><\/div><p class=\"wp-block-paragraph\">Do you need an order certificate or the ATEX documentation? See our <a href=\"https:\/\/www.valfonta.com\/en\/certificates\/\">quality certificates<\/a> or request it from our technical team.<\/p><\/section><section id=\"comparar\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">PRV55 vs. other excess pressure valves<\/h2><p class=\"wp-block-paragraph\">The range covers DN15 to DN150 and set pressures from 0.01 to 20 barg. Check whether the PRV55 is the right model or whether another one suits you better.<\/p><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-tbl vf-tbl--grid\"><table><thead><tr><th scope=\"col\">Model<\/th><th scope=\"col\">DN<\/th><th scope=\"col\">PN<\/th><th scope=\"col\">Set pressure (barg)<\/th><th scope=\"col\">Max. T (\u00b0C)<\/th><th scope=\"col\">Steam<\/th><th scope=\"col\">Body<\/th><\/tr><\/thead><tbody><tr><th scope=\"row\"><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv53\/\">PRV53<\/a><\/th><td>15 \u2013 25<\/td><td>25<\/td><td>0,5 \u2013 15<\/td><td>150<\/td><td>No<\/td><td>CF3M stainless<\/td><\/tr><tr><th scope=\"row\"><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv54\/\">PRV54<\/a><\/th><td>15 \u2013 25<\/td><td>25<\/td><td>0,5 \u2013 12<\/td><td>210<\/td><td>Yes<\/td><td>CF3M stainless<\/td><\/tr><tr><th scope=\"row\"><span class=\"vf-dato vf-dato-fila\" hidden data-vf-class=\"vf-cur\"><\/span>PRV55<\/th><td>15 \u2013 25<\/td><td>25<\/td><td>0,01 \u2013 8<\/td><td>150<\/td><td>Yes<\/td><td>CF3M stainless<\/td><\/tr><tr><th scope=\"row\"><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s1\/\">S1<\/a><\/th><td>15 \u2013 150<\/td><td>40<\/td><td>0,5 \u2013 15<\/td><td>220<\/td><td>Yes<\/td><td>WCB steel or CF3M stainless<\/td><\/tr><tr><th scope=\"row\"><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s2\/\">S2<\/a><\/th><td>15 \u2013 100<\/td><td>40<\/td><td>0,02 \u2013 10<\/td><td>180<\/td><td>Yes<\/td><td>WCB steel or CF3M stainless<\/td><\/tr><tr><th scope=\"row\"><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-relief-valve-s3\/\">S3<\/a><\/th><td>15 \u2013 150<\/td><td>40<\/td><td>0,5 \u2013 20<\/td><td>220<\/td><td>Yes<\/td><td>WCB steel or CF3M stainless<\/td><\/tr><tr><th scope=\"row\">S4<\/th><td>15 \u2013 100<\/td><td>40<\/td><td>0,5 \u2013 20<\/td><td>220<\/td><td>Yes<\/td><td>WCB steel or CF3M stainless<\/td><\/tr><\/tbody><\/table><\/figure><\/div><p class=\"vf-note wp-block-paragraph\">Data from the Valfonta excess pressure valve summary catalog (2025), except the S2 set pressure, which comes from its datasheet. All models accept liquids, oil, air, and non-flammable gases. If you are unsure whether you need an excess pressure valve or a safety valve, read <a href=\"https:\/\/www.valfonta.com\/en\/blog\/what-difference-between-safety-valve-and-relief-valve\/\">the difference between a safety valve and a relief valve<\/a>.<\/p><\/section><section id=\"preguntas\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">Frequently asked questions about the PRV55<\/h2><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>What set pressure can be adjusted with the PRV55?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">From 0.01 to 8 barg, depending on actuator size and spring (see the specifications table). The maximum inlet pressure is 16 barg.<\/p><\/div><\/details><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Can it be used with steam?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">Yes, up to 150 \u00b0C. With steam, it is installed in a horizontal pipe with the actuator facing down, with an external control line and a condensate pot filled with water, which protects the diaphragm from heat.<\/p><\/div><\/details><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>What is the difference between the PRV55 and the PRV54?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">Both are DN15 to DN25, PN25, and suitable for steam. The PRV55 has a diaphragm actuator and set pressures from 0.01 to 8 barg, up to 150 \u00b0C. The <a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv54\/\">PRV54<\/a> is bellows-balanced, has set pressures from 0.5 to 12 barg, and handles up to 210 \u00b0C.<\/p><\/div><\/details><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>What maintenance does it need?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">It requires no periodic maintenance, but the wear parts should be checked according to the service conditions. In ATEX zones, the manual specifies replacing the gaskets every 25,000 hours or whenever inspections recommend it. This can be done with the body installed, depressurized, and isolated.<\/p><\/div><\/details><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Can it be installed in an ATEX zone?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">Yes. The PRV55 carries ATEX II 2 GD marking (certificate LOM 14.034 U) and can be used in zones 1 and 2 (flammable gases, vapors, and liquids) and 21 and 22 (combustible dust), according to the temperature class that corresponds to the fluid temperature. See our article on <a href=\"https:\/\/www.valfonta.com\/en\/blog\/atex-valves\/\">ATEX valves<\/a>.<\/p><\/div><\/details><\/section><section id=\"relacionados\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">Other excess pressure valve models<\/h2><ul class=\"vf-rel wp-block-list\"><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv54\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV30-44-700x700-1.jpg\" alt=\"PRV54 excess pressure valve\" class=\"wp-image-181\" width=\"300\" height=\"300\" loading=\"lazy\"><b>PRV54 excess pressure valve<\/b><span>With bellows: set pressure from 0.5 to 12 barg and steam up to 210 \u00b0C.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-prv53\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV30-44-700x700-1.jpg\" alt=\"PRV53 excess pressure valve\" class=\"wp-image-181\" width=\"300\" height=\"300\" loading=\"lazy\"><b>PRV53 excess pressure valve<\/b><span>316L stainless, set pressure up to 15 barg and up to 150 \u00b0C, no steam.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s1\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-M1-S1-3D-700x700-1.jpg\" alt=\"S1 excess pressure valve\" class=\"wp-image-192\" width=\"300\" height=\"300\" loading=\"lazy\"><b>S1 excess pressure valve<\/b><span>From DN15 to DN150 and PN40, for steam up to 220 \u00b0C.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-excess-valve-s2\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-M2-PROVISIONAL-700x700-1.jpg\" alt=\"S2 excess pressure valve\" class=\"wp-image-193\" width=\"300\" height=\"300\" loading=\"lazy\"><b>S2 excess pressure valve<\/b><span>From DN15 to DN100, PN40, and set pressure from 0.02 barg.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/pressure-relief-valve-s3\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/valvula-alivio-presion-s3-s4-perspectiva-400.webp\" alt=\"S3 pressure relief valve\" class=\"wp-image-10230\" width=\"300\" height=\"300\" loading=\"lazy\"><b>S3 pressure relief valve<\/b><span>From DN15 to DN150, PN40, set pressure up to 20 barg and 220 \u00b0C.<\/span><\/a><\/li><\/ul><\/section><section id=\"solicitar\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-quote is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">Request a quote for the PRV55<\/h2><p class=\"wp-block-paragraph\">Give us your installation details and we will recommend the size, actuator, and spring range for your set pressure, and the diaphragm and gaskets suited to the fluid.<\/p><ul class=\"wp-block-list\"><li>Fluid and operating temperature<\/li><li>Set pressure and normal operating pressure<\/li><li>Flow rate the valve must discharge<\/li><li>Connection type (threaded or flanged)<\/li><\/ul><p class=\"vf-pdp-contact wp-block-paragraph\">You can also call <a href=\"tel:+34933720888\">933 720 888<\/a>.<\/p><\/div>\n<div class=\"wpcf7 no-js\" id=\"wpcf7-f557-o1\" lang=\"en-US\" dir=\"ltr\" data-wpcf7-id=\"557\">\n<div class=\"screen-reader-response\"><p role=\"status\" aria-live=\"polite\" aria-atomic=\"true\"><\/p> <ul><\/ul><\/div>\n<form action=\"\/en\/wp-json\/wp\/v2\/product\/657#wpcf7-f557-o1\" method=\"post\" class=\"wpcf7-form init vf-form wpcf7-acceptance-as-validation\" aria-label=\"Contact form\" novalidate=\"novalidate\" data-status=\"init\" toolname=\"solicitar_oferta\" tooldescription=\"Request a quote from Valfonta for the models on this page (model, size, fluid and pressures); a member of the team will reply.\">\n<fieldset class=\"hidden-fields-container\"><input type=\"hidden\" name=\"_wpcf7\" value=\"557\" \/><input type=\"hidden\" name=\"_wpcf7_version\" value=\"6.2.3\" \/><input type=\"hidden\" name=\"_wpcf7_locale\" value=\"en_US\" \/><input type=\"hidden\" name=\"_wpcf7_unit_tag\" value=\"wpcf7-f557-o1\" \/><input type=\"hidden\" name=\"_wpcf7_container_post\" value=\"0\" \/><input type=\"hidden\" name=\"_wpcf7_posted_data_hash\" value=\"\" \/><input type=\"hidden\" name=\"_vf_t\" value=\"1792698934.b7632b9507022157\" \/>\n<\/fieldset>\n<input class=\"wpcf7-form-control wpcf7-hidden\" value=\"PRV55\" type=\"hidden\" name=\"modelo\" \/><label>Name *<span class=\"wpcf7-form-control-wrap\" data-name=\"nombre\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text wpcf7-validates-as-required\" autocomplete=\"name\" aria-required=\"true\" aria-invalid=\"false\" value=\"\" type=\"text\" name=\"nombre\" \/><\/span><\/label><label>Company<span class=\"wpcf7-form-control-wrap\" data-name=\"empresa\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" autocomplete=\"organization\" aria-invalid=\"false\" value=\"\" type=\"text\" name=\"empresa\" \/><\/span><\/label><label>Email *<span class=\"wpcf7-form-control-wrap\" data-name=\"email\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-email wpcf7-validates-as-required wpcf7-text wpcf7-validates-as-email\" autocomplete=\"email\" aria-required=\"true\" aria-invalid=\"false\" value=\"\" type=\"email\" name=\"email\" \/><\/span><\/label><label>Phone<span class=\"wpcf7-form-control-wrap\" data-name=\"telefono\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-tel wpcf7-text wpcf7-validates-as-tel\" autocomplete=\"tel\" aria-invalid=\"false\" value=\"\" type=\"tel\" name=\"telefono\" \/><\/span><\/label><fieldset><legend>Application data (optional)<\/legend><label>Size<span class=\"wpcf7-form-control-wrap\" data-name=\"dn\"><select class=\"wpcf7-form-control wpcf7-select\" aria-invalid=\"false\" name=\"dn\"><option value=\"\">Select<\/option><option value=\"DN15 (\u00bd\u2033)\">DN15 (\u00bd\u2033)<\/option><option value=\"DN20 (\u00be\u2033)\">DN20 (\u00be\u2033)<\/option><option value=\"DN25 (1\u2033)\">DN25 (1\u2033)<\/option><option value=\"I don&#039;t know\">I don&#039;t know<\/option><\/select><\/span><\/label><label>Fluid<span class=\"wpcf7-form-control-wrap\" data-name=\"fluido\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" aria-invalid=\"false\" placeholder=\"air, nitrogen, steam, water\u2026\" value=\"\" type=\"text\" name=\"fluido\" \/><\/span><\/label><label>Set pressure (barg)<span class=\"wpcf7-form-control-wrap\" data-name=\"tarado\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" aria-invalid=\"false\" placeholder=\"e.g. 0.05\" value=\"\" type=\"text\" name=\"tarado\" \/><\/span><\/label><label>Operating pressure (barg)<span class=\"wpcf7-form-control-wrap\" data-name=\"p_servicio\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" aria-invalid=\"false\" value=\"\" type=\"text\" name=\"p_servicio\" \/><\/span><\/label><label>Flow rate to discharge<span class=\"wpcf7-form-control-wrap\" data-name=\"caudal\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" aria-invalid=\"false\" placeholder=\"e.g. 10 Nm\u00b3\/h or 2 m\u00b3\/h\" value=\"\" type=\"text\" name=\"caudal\" \/><\/span><\/label><label>Temperature (\u00b0C)<span class=\"wpcf7-form-control-wrap\" data-name=\"temperatura\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" aria-invalid=\"false\" value=\"\" type=\"text\" name=\"temperatura\" \/><\/span><\/label><\/fieldset><label class=\"vf-full\">Message<span class=\"wpcf7-form-control-wrap\" data-name=\"mensaje\"><textarea cols=\"40\" rows=\"4\" maxlength=\"2000\" class=\"wpcf7-form-control wpcf7-textarea\" aria-invalid=\"false\" name=\"mensaje\"><\/textarea><\/span><\/label><label class=\"vf-chk vf-full\"><span class=\"wpcf7-form-control-wrap\" data-name=\"privacidad\"><span class=\"wpcf7-form-control wpcf7-acceptance\"><span class=\"wpcf7-list-item\"><input type=\"checkbox\" name=\"privacidad\" value=\"1\" aria-invalid=\"false\" \/><\/span><\/span><\/span> <span>I have read and accept the <a href=\"\/en\/privacy-policy\/\">privacy policy<\/a> *<\/span><\/label><input class=\"wpcf7-form-control wpcf7-submit has-spinner vf-btn vf-btn--pri\" type=\"submit\" value=\"Send request\" \/><span class=\"vf-hp\" aria-hidden=\"true\"><label>Web <input type=\"text\" name=\"vf_web\" value=\"\" tabindex=\"-1\" autocomplete=\"off\" toolparamdescription=\"Campo de control: d\u00e9jalo vac\u00edo\"><\/label><\/span><div class=\"wpcf7-response-output\" aria-hidden=\"true\"><\/div>\n<\/form>\n<\/div>\n\n<\/div><\/section><div class=\"wp-block-group vf-pdp-bar is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><a class=\"vf-btn vf-btn--sec\" href=\"tel:+34933720888\">Call<\/a><a class=\"vf-btn vf-btn--pri\" href=\"#solicitar\">Request a quote<\/a><\/p><\/div><\/article><\/div>","protected":false},"excerpt":{"rendered":"<p>Home\u203aPressure relief valves\u203aPRV55 excess pressure valve Excess pressure valve \u00b7 Diaphragm actuator PRV55 excess pressure valve From 10 mbar Self-regulating, direct-acting excess pressure valve with a diaphragm actuator and body and internals in 316L stainless steel. It discharges the excess when the upstream pressure exceeds the set pressure, adjustable from 0.01 barg, on gases, liquids, ... <a title=\"PRV55 excess pressure valve\" class=\"read-more\" href=\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/\" aria-label=\"Read more about PRV55 excess pressure valve\">Read more<\/a><\/p>\n","protected":false},"featured_media":0,"template":"","meta":{"_acf_changed":false,"_generate-full-width-content":"true","_generate-disable-headline":"true","rank_math_title":"PRV55 diaphragm excess pressure valve | Valfonta","rank_math_description":"PRV55 excess pressure valve with diaphragm actuator and 316L stainless internals. DN15 to DN25, PN25, set pressure 0.01 to 8 barg, steam up to 150 \u00b0C.","rank_math_focus_keyword":"","vf_jsonld":"[{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.valfonta.com\/#organization\",\"name\":\"Valfonta\",\"legalName\":\"Val Fonta, S.L.\",\"taxID\":\"B59935718\",\"url\":\"https:\/\/www.valfonta.com\/en\/\",\"logo\":{\"@type\":\"ImageObject\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/valfonta-logo.webp\"},\"foundingDate\":\"1962\",\"email\":\"valfonta@valfonta.com\",\"telephone\":\"+34 933 720 888\",\"address\":{\"@type\":\"PostalAddress\",\"streetAddress\":\"C\/ Bronze 26, Pol. Ind. Les Guixeres\",\"postalCode\":\"08915\",\"addressLocality\":\"Badalona\",\"addressRegion\":\"Barcelona\",\"addressCountry\":\"ES\"},\"description\":\"Design, manufacture, and sale of pressure reducing valves, pressure relief valves, and control valves.\"},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.valfonta.com\/#website\",\"url\":\"https:\/\/www.valfonta.com\/en\/\",\"name\":\"Valfonta\",\"publisher\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"inLanguage\":\"en\"},{\"@type\":\"ItemPage\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/#webpage\",\"url\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/\",\"name\":\"PRV55 diaphragm excess pressure valve | Valfonta\",\"description\":\"PRV55 excess pressure valve with diaphragm actuator and 316L stainless internals. DN15 to DN25, PN25, set pressure 0.01 to 8 barg, steam up to 150 \u00b0C.\",\"isPartOf\":{\"@id\":\"https:\/\/www.valfonta.com\/#website\"},\"about\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"inLanguage\":\"en\",\"datePublished\":\"2020-02-05T12:10:25+02:00\",\"dateModified\":\"2026-03-19T14:24:42+02:00\",\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV45-55-700x700-1.jpg\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/#breadcrumb\"},\"mainEntity\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/#product\"}},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV45-55-700x700-1.jpg\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV45-55-700x700-1.jpg\",\"width\":\"1000\",\"height\":\"1000\",\"caption\":\"Pressure reducing valve\",\"inLanguage\":\"en\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.valfonta.com\/en\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Pressure relief valves\",\"item\":\"https:\/\/www.valfonta.com\/en\/pressure-relief-valve\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"PRV55 excess pressure valve\",\"item\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/\"}]},{\"@type\":\"Product\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/#product\",\"name\":\"PRV55 excess pressure valve\",\"url\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/\",\"description\":\"Self-regulating, direct-acting excess pressure valve with a diaphragm actuator and body and internals in 316L stainless steel. It discharges the excess when the upstream pressure exceeds the set pressure, adjustable from 0.01 barg, on gases, liquids, and steam up to 150 \u00b0C.\",\"brand\":{\"@type\":\"Brand\",\"name\":\"Valfonta\"},\"manufacturer\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"model\":\"PRV55\",\"image\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ok-PRV45-55-700x700-1.jpg\",\"material\":\"Stainless steel AISI 316L\",\"additionalProperty\":[{\"@type\":\"PropertyValue\",\"name\":\"Type\",\"value\":\"Self-regulating, direct-acting, piston-balanced excess pressure valve with diaphragm actuator\"},{\"@type\":\"PropertyValue\",\"name\":\"Sizes\",\"value\":\"DN15 (\u00bd\u2033), DN20 (\u00be\u2033), and DN25 (1\u2033)\"},{\"@type\":\"PropertyValue\",\"name\":\"Connections\",\"value\":\"BSP or NPT thread \u00b7 EN flanges \u00b7 ANSI CL150 flanges \u00b7 Clamp on request\"},{\"@type\":\"PropertyValue\",\"name\":\"Pressure rating\",\"value\":\"PN25\"},{\"@type\":\"PropertyValue\",\"name\":\"Maximum inlet pressure\",\"value\":\"16 barg\"},{\"@type\":\"PropertyValue\",\"name\":\"Set pressure range\",\"value\":\"0.01 to 8 barg, depending on actuator size and spring\"},{\"@type\":\"PropertyValue\",\"name\":\"Kv coefficient\",\"value\":\"2 m\u00b3\/h (DN15) \u00b7 2.5 m\u00b3\/h (DN20) \u00b7 3.5 m\u00b3\/h (DN25). Special Kv on request\"},{\"@type\":\"PropertyValue\",\"name\":\"Temperature\",\"value\":\"\u221210 to +150 \u00b0C (with Viton gaskets)\"},{\"@type\":\"PropertyValue\",\"name\":\"Fluids\",\"value\":\"Group 1 and 2 liquids and gases: steam, compressed air, fuel oil, water, nitrogen, inert gases\"},{\"@type\":\"PropertyValue\",\"name\":\"Materials\",\"value\":\"Body and internals in AISI 316L stainless steel. EPDM or EPDM+PTFE diaphragm. Steel sheet actuator with epoxy paint\"},{\"@type\":\"PropertyValue\",\"name\":\"Pressure sensing point\",\"value\":\"Internal or external. External required with steam and with liquids above 125 \u00b0C\"},{\"@type\":\"PropertyValue\",\"name\":\"Mounting position\",\"value\":\"Horizontal pipe. Actuator facing down with any fluid and always with steam; facing up only with gases and liquids up to 80 \u00b0C\"},{\"@type\":\"PropertyValue\",\"name\":\"Pressure Equipment Directive\",\"value\":\"PED 2014\/68\/EU, Article 4.3: CE marking not required (Group 1 and 2 fluids)\"},{\"@type\":\"PropertyValue\",\"name\":\"ATEX\",\"value\":\"II 2 GD c IIC Tx \/ c IIIC Tx\u00baC \u00b7 certificate LOM 14.034 U\"},{\"@type\":\"PropertyValue\",\"name\":\"On request\",\"value\":\"RG10 bronze body \u00b7 stainless steel actuator \u00b7 special gaskets \u00b7 special Kv\"}],\"category\":\"Pressure relief valves\",\"subjectOf\":[{\"@type\":\"DigitalDocument\",\"name\":\"PRV55 datasheet (in English)\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/PRV55-16B-ENG.pdf\",\"encodingFormat\":\"application\/pdf\"},{\"@type\":\"DigitalDocument\",\"name\":\"Operation and installation manual (in English)\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/Manual-PRV55-16B-ENG.pdf\",\"encodingFormat\":\"application\/pdf\"}]},{\"@type\":\"FAQPage\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/excess-pressure-valve-model-prv55\/#faq\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What set pressure can be adjusted with the PRV55?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"From 0.01 to 8 barg, depending on actuator size and spring (see the specifications table). The maximum inlet pressure is 16 barg.\"}},{\"@type\":\"Question\",\"name\":\"Can it be used with steam?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes, up to 150 \u00b0C. With steam, it is installed in a horizontal pipe with the actuator facing down, with an external control line and a condensate pot filled with water, which protects the diaphragm from heat.\"}},{\"@type\":\"Question\",\"name\":\"What is the difference between the PRV55 and the PRV54?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Both are DN15 to DN25, PN25, and suitable for steam. The PRV55 has a diaphragm actuator and set pressures from 0.01 to 8 barg, up to 150 \u00b0C. The PRV54 is bellows-balanced, has set pressures from 0.5 to 12 barg, and handles up to 210 \u00b0C.\"}},{\"@type\":\"Question\",\"name\":\"What maintenance does it need?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"It requires no periodic maintenance, but the wear parts should be checked according to the service conditions. In ATEX zones, the manual specifies replacing the gaskets every 25,000 hours or whenever inspections recommend it. This can be done with the body installed, depressurized, and isolated.\"}},{\"@type\":\"Question\",\"name\":\"Can it be installed in an ATEX zone?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. The PRV55 carries ATEX II 2 GD marking (certificate LOM 14.034 U) and can be used in zones 1 and 2 (flammable gases, vapors, and liquids) and 21 and 22 (combustible dust), according to the temperature class that corresponds to the fluid temperature. See our article on ATEX valves.\"}}]}]}]"},"product_brand":[],"product_cat":[79],"product_tag":[],"class_list":["post-657","product","type-product","status-publish","product_cat-sin-categorizar","first","instock","shipping-taxable","product-type-simple"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/product\/657","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/types\/product"}],"wp:attachment":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/media?parent=657"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/product_brand?post=657"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/product_cat?post=657"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/product_tag?post=657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}