{"id":668,"date":"2026-10-02T13:17:56","date_gmt":"2026-10-02T11:17:56","guid":{"rendered":"https:\/\/www.valfonta.com\/producto\/progressive-opening-safety-valve\/"},"modified":"2026-10-22T09:21:45","modified_gmt":"2026-10-22T07:21:45","slug":"progressive-opening-safety-valve","status":"publish","type":"product","link":"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/","title":{"rendered":"368 \u2013 371 progressive-opening safety 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\/safety-valves\/\">Safety valves<\/a><span class=\"vf-sep\" aria-hidden=\"true\">\u203a<\/span><span aria-current=\"page\">368 \u2013 371 progressive-opening safety valve<\/span><\/p><\/nav><article class=\"wp-block-group vf-pdp vfd-model--368%E2%80%93371 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\">Safety valve \u00b7 Progressive opening<\/p><h1 class=\"wp-block-heading\">368 \u2013 371 progressive-opening safety 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\">Progressive opening<\/span><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/alivio-368-700x700-1.jpg\" alt=\"Figure 368 progressive-opening safety valve in brass with lever and threaded connection\" class=\"wp-image-196\" 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\">Progressive-opening safety valve in brass\/bronze that detects overpressure in tanks, boilers, or pipes and discharges the excess fluid without auxiliary power. It is made in two figures: 368, with open discharge, and 371, with piped discharge.<\/p><ul class=\"vf-pdp-keys wp-block-list\"><li><span>Sizes<\/span><b>3\/8\u2033 to 3\u2033<\/b><\/li><li><span>Opening<\/span><b>Progressive<\/b><\/li><li><span>Discharge<\/span><b>Open (368) \u00b7 piped (371)<\/b><\/li><li><span>Set pressure ranges<\/span><b>0\u20131 \u00b7 1\u201311 \u00b7 11\u201316 bar<\/b><\/li><li><span>Pressure rating<\/span><b>PN16 bronze seat \u00b7 PN12 Viton<\/b><\/li><li><span>Max. temperature<\/span><b>180 \u00b0C<\/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\/ALIVIO-11-ESP.pdf\" target=\"_blank\" rel=\"noopener\">Download datasheet <small>PDF<\/small><\/a><\/p><\/div><p class=\"vf-pdp-contact wp-block-paragraph\">Questions about the set pressure? 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>PED 2014\/68\/EU certificate<\/li><li>Bench-tested with compressed air<\/li><li>Supplied set to the pressure you specify<\/li><li>Numbered main components<\/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=\"#documentacion\">Documentation<\/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 368\u2013371 valve is used for<\/h2><p class=\"wp-block-paragraph\">It is a progressive-opening <a href=\"https:\/\/www.valfonta.com\/en\/safety-valves\/\">safety valve<\/a>: when the pressure exceeds the set pressure, it starts to open and discharges the excess fluid; once the pressure returns to normal, it closes again. It works with liquids, compressed air, inert gases, and steam. If you are unsure whether you need a safety valve or a relief 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><\/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 368\u2013371 valve if\u2026<\/h3><ul class=\"vf-si wp-block-list\"><li>You want progressive opening rather than instantaneous pop action.<\/li><li>You work with liquids, compressed air, inert gases, or steam up to 180 \u00b0C.<\/li><\/ul><h3 class=\"wp-block-heading\">Choose another model if\u2026<\/h3><ul class=\"vf-no wp-block-list\"><li>You need full, instantaneous opening: see the <a href=\"https:\/\/www.valfonta.com\/en\/product\/alper-fully-open-safety-valve\/\">ALPER<\/a> (up to PN25 and 280 \u00b0C) or the <a href=\"https:\/\/www.valfonta.com\/en\/product\/safety-valves-for-boilers-jas\/\">JAS<\/a> (\u00bc\u2033 to \u00be\u2033).<\/li><li>You need to protect a tank against vacuum: see the <a href=\"https:\/\/www.valfonta.com\/en\/product\/alper-atmospheric-valves\/\">ALPER atmospheric valves<\/a>.<\/li><li>You need flanged connections or sizes up to DN150: see the <a href=\"https:\/\/www.valfonta.com\/en\/pressure-relief-valve\/\">pressure relief valves<\/a>.<\/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\">368\u2013371 valve 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>Progressive-opening safety valve (relief)<\/td><\/tr><tr><th scope=\"row\">Figures<\/th><td>368: open discharge \u00b7 371: piped discharge<\/td><\/tr><tr><th scope=\"row\">Sizes<\/th><td>368: \u00bd\u2033 to 3\u2033 \u00b7 371: 3\/8\u2033 to 3\u2033, with an outlet the same size as the inlet<\/td><\/tr><tr><th scope=\"row\">Connections<\/th><td>Inlet: BSP male thread \u00b7 Outlet (371): BSP female thread<\/td><\/tr><tr><th scope=\"row\">Material<\/th><td>Brass \/ bronze<\/td><\/tr><tr><th scope=\"row\">Seat and pressure rating<\/th><td>Bronze seat: PN16, 0\u20131 and 11\u201316 bar ranges \u00b7 Viton seat: PN12, 1\u201311 bar range<\/td><\/tr><tr><th scope=\"row\">Fluids<\/th><td>Liquids, compressed air, inert gases, and steam<\/td><\/tr><tr><th scope=\"row\">Maximum temperature<\/th><td>180 \u00b0C<\/td><\/tr><tr><th scope=\"row\">Test<\/th><td>On a test bench with compressed air at ambient temperature; supplied set to the requested pressure<\/td><\/tr><tr><th scope=\"row\">Certification<\/th><td>PED 2014\/68\/EU. Material, heat, and output certificates if requested in advance<\/td><\/tr><tr><th scope=\"row\">Other options<\/th><td>AISI 302\/316 stainless steel spring \u00b7 NPT thread<\/td><\/tr><\/tbody><\/table><\/figure><\/div><\/section><section id=\"funcionamiento\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">How it works<\/h2><ol class=\"vf-steps wp-block-list\"><li><b>Closed in service.<\/b> The spring, set to the requested pressure, holds the plug on the seat.<\/li><li><b>Progressive opening.<\/b> If the pressure exceeds the set pressure, the valve opens progressively, not all at once like a full, instantaneous-opening valve.<\/li><li><b>Closing.<\/b> When the pressure returns to normal, the valve closes again.<\/li><\/ol><\/section><section id=\"documentacion\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">368\u2013371 valve 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>368\u2013371 datasheet<\/b><span>PDF \u00b7 1 page \u00b7 features, materials, and sizes<\/span><\/p><\/div><p class=\"vf-enllac wp-block-paragraph\"><a class=\"vf-enllac-estirat\" href=\"\/wp-content\/uploads\/2026\/10\/ALIVIO-11-ESP.pdf\" aria-label=\"PDF 368\u2013371 datasheet PDF \u00b7 1 page \u00b7 features, materials, and sizes\" target=\"_blank\" rel=\"noopener\"><\/a><\/p><\/div><\/div><\/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 368\u2013371 valve<\/h2><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>What is the difference between figure 368 and figure 371?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">The 368 discharges directly to atmosphere (open discharge) and has only an inlet, with a BSP male thread. The 371 adds an outlet with a BSP female thread to pipe away the discharge.<\/p><\/div><\/details><details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>What set pressure does it accept?<\/summary><div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">It depends on the seat: with a bronze seat, ranges from 0 to 1 bar and from 11 to 16 bar (PN16); with a Viton seat, from 1 to 11 bar (PN12). The valve is supplied set to the pressure you specify.<\/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 180 \u00b0C. It also handles liquids, compressed air, and inert gases.<\/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 Valfonta safety valves<\/h2><ul class=\"vf-rel wp-block-list\"><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/alper-fully-open-safety-valve\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/alper-1.jpg\" alt=\"ALPER safety valve\" class=\"wp-image-165\" width=\"300\" height=\"300\" loading=\"lazy\"><b>ALPER safety valve<\/b><span>Full, instantaneous opening, bronze or stainless, up to PN25 and 280 \u00b0C.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/safety-valves-for-boilers-jas\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/jas-1.jpg\" alt=\"JAS safety valve\" class=\"wp-image-211\" width=\"300\" height=\"300\" loading=\"lazy\"><b>JAS safety valve<\/b><span>Full, instantaneous opening in brass, \u00bc\u2033 to \u00be\u2033, PN16.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/product\/alper-atmospheric-valves\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/alperatmos-2.jpg\" alt=\"ALPER atmospheric valves\" class=\"wp-image-212\" width=\"300\" height=\"300\" loading=\"lazy\"><b>ALPER atmospheric valves<\/b><span>Tank protection against vacuum and overpressure.<\/span><\/a><\/li><li><a href=\"https:\/\/www.valfonta.com\/en\/pressure-relief-valve\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/valvula-alivio-presion-s3-s4-perspectiva-400.webp\" alt=\"Pressure relief valves\" class=\"wp-image-10230\" width=\"300\" height=\"300\" loading=\"lazy\"><b>Pressure relief valves<\/b><span>S1\u2013S4 and PRV53\u201355 range, from DN15 to DN150 and set pressure up to 20 barg.<\/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 368\u2013371 valve<\/h2><p class=\"wp-block-paragraph\">Give us your installation details and we will recommend the right figure, size, and seat.<\/p><ul class=\"wp-block-list\"><li>Fluid and temperature<\/li><li>Set pressure<\/li><li>Figure: open discharge (368) or piped discharge (371)<\/li><li>Connection size and seat type<\/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-f567-o1\" lang=\"en-US\" dir=\"ltr\" data-wpcf7-id=\"567\">\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\/668#wpcf7-f567-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=\"567\" \/><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-f567-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=\"1792698949.82289d9397206132\" \/>\n<\/fieldset>\n<input class=\"wpcf7-form-control wpcf7-hidden\" value=\"368\u2013371\" 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=\"3\/8\u2033\">3\/8\u2033<\/option><option value=\"\u00bd\u2033\">\u00bd\u2033<\/option><option value=\"\u00be\u2033\">\u00be\u2033<\/option><option value=\"1\u2033\">1\u2033<\/option><option value=\"1\u00bc\u2033\">1\u00bc\u2033<\/option><option value=\"1\u00bd\u2033\">1\u00bd\u2033<\/option><option value=\"2\u2033\">2\u2033<\/option><option value=\"2\u00bd\u2033\">2\u00bd\u2033<\/option><option value=\"3\u2033\">3\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, steam, water\u2026\" value=\"\" type=\"text\" name=\"fluido\" \/><\/span><\/label><label>Set pressure (bar)<span class=\"wpcf7-form-control-wrap\" data-name=\"tarado\"><input size=\"40\" maxlength=\"400\" class=\"wpcf7-form-control wpcf7-text\" aria-invalid=\"false\" value=\"\" type=\"text\" name=\"tarado\" \/><\/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\u203aSafety valves\u203a368 \u2013 371 progressive-opening safety valve Safety valve \u00b7 Progressive opening 368 \u2013 371 progressive-opening safety valve Progressive opening Progressive-opening safety valve in brass\/bronze that detects overpressure in tanks, boilers, or pipes and discharges the excess fluid without auxiliary power. It is made in two figures: 368, with open discharge, and 371, with piped ... <a title=\"368 \u2013 371 progressive-opening safety valve\" class=\"read-more\" href=\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/\" aria-label=\"Read more about 368 \u2013 371 progressive-opening safety 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":"Progressive-opening safety valve | Valfonta","rank_math_description":"Progressive-opening safety valve in brass\/bronze, fig. 368 (open discharge) and 371 (piped discharge). 3\/8\u2033 to 3\u2033, set pressure 0 to 16 bar, up to 180 \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\/progressive-opening-safety-valve\/#webpage\",\"url\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/\",\"name\":\"Progressive-opening safety valve | Valfonta\",\"description\":\"Progressive-opening safety valve in brass\/bronze, fig. 368 (open discharge) and 371 (piped discharge). 3\/8\u2033 to 3\u2033, set pressure 0 to 16 bar, up to 180 \u00b0C.\",\"isPartOf\":{\"@id\":\"https:\/\/www.valfonta.com\/#website\"},\"about\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"inLanguage\":\"en\",\"datePublished\":\"2020-02-06T12:17:23+02:00\",\"dateModified\":\"2025-12-19T10:52:03+02:00\",\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/alivio-368-700x700-1.jpg\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/#breadcrumb\"},\"mainEntity\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/#product\"}},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/alivio-368-700x700-1.jpg\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/alivio-368-700x700-1.jpg\",\"width\":\"1000\",\"height\":\"1000\",\"caption\":\"Safety valve\",\"inLanguage\":\"en\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.valfonta.com\/en\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Safety valves\",\"item\":\"https:\/\/www.valfonta.com\/en\/safety-valves\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"368 \u2013 371 progressive-opening safety valve\",\"item\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/\"}]},{\"@type\":\"Product\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/#product\",\"name\":\"368 \u2013 371 progressive-opening safety valve\",\"url\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/\",\"description\":\"Progressive-opening safety valve in brass\/bronze that detects overpressure in tanks, boilers, or pipes and discharges the excess fluid without auxiliary power. 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Material, heat, and output certificates if requested in advance\"},{\"@type\":\"PropertyValue\",\"name\":\"Other options\",\"value\":\"AISI 302\/316 stainless steel spring \u00b7 NPT thread\"}],\"category\":\"Safety valves\",\"subjectOf\":[{\"@type\":\"DigitalDocument\",\"name\":\"368\u2013371 datasheet\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/ALIVIO-11-ESP.pdf\",\"encodingFormat\":\"application\/pdf\"}]},{\"@type\":\"FAQPage\",\"@id\":\"https:\/\/www.valfonta.com\/en\/product\/progressive-opening-safety-valve\/#faq\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What is the difference between figure 368 and figure 371?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The 368 discharges directly to atmosphere (open discharge) and has only an inlet, with a BSP male thread. 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