{"id":610,"date":"2026-02-10T17:04:13","date_gmt":"2026-02-10T16:04:13","guid":{"rendered":"https:\/\/www.valfonta.com\/blog\/cavitation-in-valves\/"},"modified":"2026-10-15T12:10:52","modified_gmt":"2026-10-15T10:10:52","slug":"cavitation-in-valves","status":"publish","type":"post","link":"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/","title":{"rendered":"Cavitation in pressure reducing valves: causes, solutions, and recommendations"},"content":{"rendered":"<div class=\"wp-block-group vf-raiz vf-pl-articulo is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-cat-wrap is-layout-flow wp-block-group-is-layout-flow\"><article class=\"wp-block-group vf-pdp vf-post 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\">\u203a<\/span><a href=\"\/en\/blog\/\">Blog<\/a><span class=\"vf-sep\">\u203a<\/span><span aria-current=\"page\">Cavitation in pressure reducing valves: causes, solutions, and recommendations<\/span><\/p><\/nav><header class=\"wp-block-group vf-post-head is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-pdp-eyebrow wp-block-paragraph\"><a href=\"\/en\/pressure-reducing-valves\/\">Pressure reducing valves<\/a><\/p><h1 class=\"wp-block-heading\">Cavitation in pressure reducing valves: causes, solutions, and recommendations<\/h1><p class=\"vf-post-meta wp-block-paragraph\"><span>By H\u00e8ctor<\/span><span><time datetime=\"2026-04-29\">Updated April 29, 2026<\/time><\/span><span>8 min read<\/span><\/p><\/header><figure class=\"wp-block-image size-full vf-post-hero is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\" alt=\"Cavitation in pressure reducing valves: causes, solutions, and recommendations\" class=\"wp-image-225\" width=\"1200\" height=\"514\"\/><\/figure><div class=\"wp-block-group vf-post-grid is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-post-body is-layout-flow wp-block-group-is-layout-flow\"><aside class=\"wp-block-group vf-post-summary vfa-aria-label--In%20summary is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-t wp-block-paragraph\">In summary<\/p><p class=\"wp-block-paragraph\">Cavitation in a pressure reducing valve occurs when the pressure drops below the vapor pressure at the vena contracta and the bubbles collapse as pressure recovers downstream, eroding the seat, plug, and body. It shows up as pitting, seat leakage, and a gravel-like noise. It is assessed with the sigma index (\u03c3): below 1.5, a standard globe valve cannot withstand it. It is corrected by sizing on Kv, with hardened Stellite internals, and by reducing the pressure in two or more stages.<\/p><\/aside><details class=\"wp-block-details vf-post-toc-m is-layout-flow wp-block-details-is-layout-flow\"><summary>Article contents<\/summary><ol class=\"wp-block-list\"><li><a href=\"#diagnostico-de-la-cavitacion-en-procesos-de-reduccion-de-pre\">Diagnosing cavitation in pressure reduction processes<\/a><\/li><li><a href=\"#optimizacion-del-diseno-y-seleccion-de-materiales-para-mitig\">Optimizing design and material selection to mitigate wear<\/a><\/li><li><a href=\"#gestion-del-ciclo-de-vida-y-cumplimiento-de-la-directiva-ped\">Life cycle management and compliance with the PED 2014\/68\/EU Directive<\/a><\/li><\/ol><\/details><h2 class=\"wp-block-heading\" id=\"diagnostico-de-la-cavitacion-en-procesos-de-reduccion-de-pre\"><strong>Diagnosing cavitation in pressure reduction processes<\/strong><\/h2><p class=\"wp-block-paragraph\">Cavitation is one of the most destructive phenomena in fluid engineering, especially in <strong>pressure reducing valves (PRVs)<\/strong>.<\/p><p class=\"wp-block-paragraph\">This phenomenon occurs when, due to a high velocity through the regulating orifice, the static pressure of the fluid drops below its <strong>vapor pressure (P<sub>v<\/sub>)<\/strong>. At that instant, the liquid vaporizes locally, forming vapor bubbles. As the fluid moves toward the outlet zone (downstream), the pressure recovers above the vapor pressure. <\/p><p class=\"wp-block-paragraph\">This causes those bubbles to collapse violently, generating microscopic shock waves with localized pressures that can exceed <strong>1,000 bar<\/strong>. These forces exceed the yield strength of virtually any commercial metal alloy.<\/p><h3 class=\"wp-block-heading\" id=\"dinamica-de-fluidos-del-flasheo-a-la-formacion-de-microburbu\"><strong>Fluid dynamics: from flashing to microbubble formation<\/strong><\/h3><p class=\"wp-block-paragraph\">To understand the risk of cavitation in an installation, we must analyze the critical pressure differential. The process begins at the <strong>vena contracta<\/strong>, which is the point of minimum flow area and maximum velocity just downstream of the plug.<\/p><p class=\"wp-block-paragraph\">If the pressure at the vena contracta drops below the P<sub>v<\/sub> of the fluid at the operating temperature, the cavitation phase begins.\u00a0<\/p><p class=\"wp-block-paragraph\">It is essential not to confuse this process with <strong>\u201cflashing\u201d<\/strong>. In flashing, the outlet pressure (P<sub>2<\/sub>) remains below the vapor pressure and the fluid leaves as a two-phase flow (liquid-vapor mixture). In cavitation, by contrast, the pressure P<sub>2<\/sub> is higher than P<sub>v<\/sub>, which forces sudden, violent recondensation.<\/p><p class=\"wp-block-paragraph\">At Valfonta, we recommend calculating the <strong>sigma cavitation index (\u03c3)<\/strong> to determine whether the operating regime of models such as the <strong>PRV 30<\/strong> or the <strong>M1<\/strong> is in the risk zone.<\/p><h3 class=\"wp-block-heading\" id=\"identificacion-de-danos-erosion-por-picadura-y-degradacion-m\"><strong>Identifying damage: pitting erosion and mechanical degradation<\/strong><\/h3><p class=\"wp-block-paragraph\">Cavitation damage is easy to identify during preventive maintenance shutdowns and is usually concentrated in the valve internals. The technical indicators of this severe wear include:<\/p><div class=\"wp-block-group vf-t-ul is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Pitting erosion:<\/strong> The material has a \u201cspongy\u201d or porous appearance, similar to a surface attacked by acid.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Loss of tightness:<\/strong> Wear on the <strong>seat<\/strong> and the <strong>plug<\/strong> prevents tight shutoff, making it impossible to meet leakage <strong>Class IV or VI<\/strong>.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Body degradation:<\/strong> In severe cases, the micro-implosions can perforate the body walls, even in <strong>AISI 316L (CF3M) stainless steel<\/strong>.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Line contamination:<\/strong> The eroded metal breaks away as fine particles that can damage downstream equipment, such as heat exchangers or sensitive instrumentation.<\/p><\/div><\/div><h3 class=\"wp-block-heading\" id=\"vibracion-y-ruido-senales-criticas-de-inestabilidad-hidrauli\"><strong>Vibration and noise: critical signs of hydraulic instability<\/strong><\/h3><p class=\"wp-block-paragraph\">An unmistakable symptom of cavitation in the plant is the characteristic noise, often described by maintenance engineers as gravel passing through the pipe.<\/p><p class=\"wp-block-paragraph\">The mechanical effects of this instability can be summarized as follows:<\/p><div class=\"wp-block-group vf-t-ul is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Broadband noise:<\/strong> Unlike the constant hiss of aerodynamic noise, cavitation produces an erratic sound that can exceed <strong>100 dB<\/strong>.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Induced mechanical fatigue:<\/strong> High-frequency vibration accelerates fatigue failure of internal components such as the <strong>sealing bellows<\/strong> or the connecting bolts.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Set point instability:<\/strong> Bubble formation in the orifice alters the actual <strong>flow coefficient (Kv)<\/strong>, causing oscillations in the downstream pressure.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Damage to surrounding instrumentation:<\/strong> Vibrations are transmitted through the piping, affecting the accuracy of <strong>pressure gauges<\/strong> and the integrity of <strong>pressure transmitters<\/strong>.<\/p><\/div><\/div><h2 class=\"wp-block-heading\" id=\"optimizacion-del-diseno-y-seleccion-de-materiales-para-mitig\"><strong>Optimizing design and material selection to mitigate wear<\/strong><\/h2><p class=\"wp-block-paragraph\">The definitive solution to cavitation is not simply replacing a damaged valve with an identical new one, but reassessing the process conditions.<\/p><p class=\"wp-block-paragraph\">At Valfonta, we address this problem through application engineering, working on two fronts: <strong>correct hydraulic sizing<\/strong> and <strong>advanced metallurgical selection<\/strong>.<\/p><h3 class=\"wp-block-heading\" id=\"el-coeficiente-de-cavitacion-sigma-y-el-dimensionamiento-del\"><strong>The cavitation coefficient (\u03c3) and the sizing of K<sub>v<\/sub><\/strong><\/h3><p class=\"wp-block-paragraph\">The first step is to calculate the cavitation index (\u03c3) of the application. This dimensionless value relates the differential pressure to the difference between the inlet pressure and the vapor pressure.<\/p><p class=\"wp-block-paragraph\">A common mistake in the plant is selecting the valve based solely on the pipe diameter (line size), which often results in <strong>oversized valves<\/strong>. An oversized valve operates very close to its seat (openings &lt;10%), where fluid velocity is at its maximum and the risk of cavitation soars.<\/p><p class=\"wp-block-paragraph\">Below is the reference table our engineering office uses to determine service severity:<\/p><div class=\"wp-block-group vf-tbl-wrap is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-table vf-post-table\"><table><thead><tr><th><strong>Cavitation index (\u03c3)<\/strong><\/th><th><strong>Flow regime diagnosis<\/strong><\/th><th><strong>Recommended engineering action<\/strong><\/th><\/tr><\/thead><tbody><tr><td><strong>\u03c3 &gt; 2.0<\/strong><\/td><td>Subcritical flow (safe)<\/td><td>Standard valve (stainless or soft seat).<\/td><\/tr><tr><td><strong>1.5 &lt; \u03c3 &lt; 2.0<\/strong><\/td><td>Incipient cavitation<\/td><td>Requires hardened internals (Stellite trim).<\/td><\/tr><tr><td><strong>1.0 &lt; \u03c3 &lt; 1.5<\/strong><\/td><td>Severe cavitation<\/td><td>Mandatory: anti-cavitation cage or staged reduction.<\/td><\/tr><tr><td><strong>\u03c3 &lt; 1.0<\/strong><\/td><td>Flashing (complete vaporization)<\/td><td>Line redesign, larger outlet diameter, or special nozzle.<\/td><\/tr><\/tbody><\/table><\/figure><\/div><p class=\"wp-block-paragraph\"><em>If the calculation yields a value below 1.5, a standard globe valve will not survive, regardless of the brand.<\/em><\/p><h3 class=\"wp-block-heading\" id=\"materiales-de-alta-resistencia-del-acero-inoxidable-cf3m-a-l\"><strong>High-resistance materials: from CF3M stainless steel to Stellite hardfacing<\/strong><\/h3><p class=\"wp-block-paragraph\">When the process conditions cannot be changed (e.g., limited space that prevents staged reduction), metallurgy is the last line of defense.<\/p><p class=\"wp-block-paragraph\">The Valfonta standard uses <strong>AISI 316L (CF3M) stainless steel<\/strong> in bodies and internals. This material offers excellent resistance to chemical corrosion, but has limitations against the extreme mechanical erosion caused by bubble implosion.<\/p><p class=\"wp-block-paragraph\">For high-\u0394P applications, we apply a <strong>hardfacing<\/strong> process (surface hardening). The most effective solution is to apply <strong>Stellite Grade 6<\/strong> (a cobalt-chromium-tungsten alloy) to the sealing surfaces of the plug and seat.<\/p><div class=\"wp-block-group vf-t-ul is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\">This alloy raises hardness to <strong>40-45 HRC<\/strong> (Rockwell C).<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\">It retains its mechanical properties up to <strong>500 \u00b0C<\/strong>, ideal for superheated steam lines.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\">It significantly delays the onset of <i>pitting<\/i>, extending the MTBF (Mean Time Between Failures).<\/p><\/div><\/div><h3 class=\"wp-block-heading\" id=\"implementacion-de-etapas-de-reduccion-multiple-y-orificios-d\"><strong>Implementing multistage reduction and restriction orifices<\/strong><\/h3><p class=\"wp-block-paragraph\">The most robust strategy from a physical standpoint is to prevent the pressure from dropping below the vapor pressure in a single step. To do this, we split the total pressure drop (\u0394P) into two or more consecutive stages (\u0394P<sub>1<\/sub> + \u0394P<sub>2<\/sub>).<\/p><p class=\"wp-block-paragraph\">This is achieved by installing two valves in series or through integrated solutions.<\/p><p class=\"wp-block-paragraph\">At Valfonta, we recommend the following configurations for our <strong>PRV<\/strong> and <strong>M1 series<\/strong> models:<\/p><div class=\"wp-block-group vf-t-ul is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Cascade installation:<\/strong> Install two reducing valves in series. The first reduces, for example, from 10 to 5 bar, and the second from 5 to 2 bar. Both operate in the safe zone (\u03c3 &gt; 2.0).<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Orifice plates (restrictors):<\/strong> We install a plate with a calibrated orifice immediately downstream of the valve. This plate creates an immediate artificial back pressure, raising the local P<sub>2<\/sub> at the valve and preventing vaporization.<\/p><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><i><\/i><\/p><p class=\"wp-block-paragraph\"><strong>Seat and plug design:<\/strong> In the <strong>M1<\/strong> models, the balanced plug design makes it possible to handle higher differentials without instability, but it must always be verified that the outlet velocity in the body does not exceed sonic limits (Mach &gt; 0.3) in gases or 5 m\/s in liquids, to avoid additional erosion.<\/p><\/div><\/div><h2 class=\"wp-block-heading\" id=\"gestion-del-ciclo-de-vida-y-cumplimiento-de-la-directiva-ped\"><strong>Life cycle management and compliance with the PED 2014\/68\/EU Directive<\/strong><\/h2><p class=\"wp-block-paragraph\">Cavitation should not be treated solely as an operational noise or vibration problem, but as a<strong> direct risk to industrial safety that<\/strong> <strong>compromises the integrity of pressure equipment.<\/strong> A valve weakened by systematic internal erosion can suffer a catastrophic failure in the body or the bonnet assembly, releasing fluid at high pressure and temperature.\u00a0<\/p><p class=\"wp-block-paragraph\">For this reason, all pressure reducing valves and control valves manufactured by Valfonta are designed, calculated, and certified to the strict requirements of the Pressure Equipment Directive 2014\/68\/EU (PED), ensuring that wall thickness and material selection withstand the mechanical stress conditions.<\/p><p class=\"wp-block-paragraph\">To guarantee this operational safety over time, it is imperative to establish a predictive maintenance protocol that does not rely solely on detecting external leaks. During technical shutdowns<strong>, maintenance personnel must remove the internals to visually inspect the plug and seat for signs of <\/strong><strong><i>pitting<\/i><\/strong><strong> or microcraters,<\/strong> which indicate an active cavitation regime that requires immediate correction.\u00a0<\/p><p class=\"wp-block-paragraph\">Likewise, in valves fitted with a sealing bellows for thermal or hazardous fluids, the integrity of the stainless steel convolutions must be checked, since the high-frequency vibration generated by bubble implosion is the main cause of fatigue and cracking in these critical components, compromising tightness to atmosphere.<\/p><h3 class=\"wp-block-heading\" id=\"consultoria-tecnica-para-el-calculo-de-aplicaciones-criticas\"><strong>Technical consulting for sizing critical applications<\/strong><\/h3><p class=\"wp-block-paragraph\">The most cost-effective way to eliminate cavitation is not the repeated replacement of damaged valves, but the thermodynamic redesign of the control point. At Valfonta\u2019s engineering office in Barcelona, we do not simply supply catalog references; we analyze the physics of your installation to determine whether your process requires a straight-through valve, an anti-cavitation cage, or a staged reduction system.\u00a0<\/p><p class=\"wp-block-paragraph\">To do this, plant managers need to provide the actual process data, including the inlet pressure, the required outlet pressure, the mass or volumetric flow rate, and the operating temperature.\u00a0<\/p><p class=\"wp-block-paragraph\">With this information, our engineering team will calculate the exact sigma coefficient and design a custom solution, ensuring stable, quiet, and long-lasting operation that protects both your asset investment and the safety of your personnel.<\/p><\/div><aside class=\"wp-block-group vf-post-aside is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-post-sticky is-layout-flow wp-block-group-is-layout-flow\"><nav class=\"wp-block-group vf-post-toc vfa-aria-label--Article%20contents is-layout-flow wp-block-group-is-layout-flow\"><p class=\"wp-block-paragraph\">In this article<\/p><ol class=\"wp-block-list\"><li><a href=\"#diagnostico-de-la-cavitacion-en-procesos-de-reduccion-de-pre\">Diagnosing cavitation in pressure reduction processes<\/a><\/li><li><a href=\"#optimizacion-del-diseno-y-seleccion-de-materiales-para-mitig\">Optimizing design and material selection to mitigate wear<\/a><\/li><li><a href=\"#gestion-del-ciclo-de-vida-y-cumplimiento-de-la-directiva-ped\">Life cycle management and compliance with the PED 2014\/68\/EU Directive<\/a><\/li><\/ol><\/nav><div class=\"wp-block-group vf-post-cta is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-t wp-block-paragraph\">Do you need a pressure reducing valve?<\/p><p class=\"wp-block-paragraph\">We help you choose the right model and size for your installation.<\/p><p class=\"vf-envolt wp-block-paragraph\"><a class=\"vf-btn vf-btn--pri\" href=\"#contactar\">Request a quote<\/a><\/p><p class=\"vf-envolt wp-block-paragraph\"><a class=\"vf-btn vf-btn--sec\" href=\"\/en\/pressure-reducing-valves\/\">View pressure reducing valves<\/a><\/p><p class=\"vf-tel wp-block-paragraph\">Or call <a href=\"tel:+34933720888\">933 720 888<\/a><\/p><\/div><\/div><\/aside><\/div><section id=\"valvulas\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">Related valves<\/h2><ul class=\"vf-rel wp-block-list\"><li><a href=\"\/en\/product\/pressure-reducing-valves-m1\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/valvula-reductora-presion-m1-perspectiva-400.webp\" alt=\"M1 reducing valve\" class=\"wp-image-201\" width=\"300\" height=\"300\" loading=\"lazy\"><b>M1 reducing valve<\/b><span>Up to DN150 and 220 \u00b0C, for steam.<\/span><\/a><\/li><li><a href=\"\/en\/product\/pressure-reducing-valve-vd\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/valvula-reductora-presion-vd-perspectiva-400.webp\" alt=\"VD reducing valve\" class=\"wp-image-10116\" width=\"300\" height=\"300\" loading=\"lazy\"><b>VD reducing valve<\/b><span>From DN15 to DN100, up to 40 bar, and steam up to 200 \u00b0C.<\/span><\/a><\/li><li><a href=\"\/en\/product\/pressure-reducing-valve-prv30\/\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/valvula-reductora-presion-prv30-frontal-400.webp\" alt=\"PRV30 reducing valve\" class=\"wp-image-199\" width=\"300\" height=\"300\" loading=\"lazy\"><b>PRV30 reducing valve<\/b><span>316L stainless, from DN15 to DN25, threaded or flanged, up to 25 bar.<\/span><\/a><\/li><\/ul><p class=\"vf-post-more wp-block-paragraph\"><a href=\"\/en\/pressure-reducing-valves\/\">View all pressure reducing valves \u2192<\/a><\/p><\/section><section id=\"articulos\" class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><h2 class=\"wp-block-heading\">Related articles<\/h2><div class=\"wp-block-group vf-post-cards vf-t-ul is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-amb-enllac is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-image vf-img-suelta\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/detalle-eyector-Valfonta.jpg\" alt=\"\" class=\"wp-image-231\" width=\"400\" height=\"225\" loading=\"lazy\"><\/figure><div class=\"wp-block-group vf-in is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><small>Pressure reducing valves<\/small><b>Pressure reducing valve symbols: characteristics and representations<\/b><span>6 min read<\/span><\/p><\/div><p class=\"vf-enllac wp-block-paragraph\"><a class=\"vf-enllac-estirat\" href=\"\/en\/blog\/pressure-reducing-valves-symbology\/\" aria-label=\"Pressure reducing valves Pressure reducing valve symbols: characteristics and representations 6 min read\"><\/a><\/p><\/div><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-amb-enllac is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-image vf-img-suelta\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/engineering-communications-at-the-gas-station-KGAC2SB.jpg\" alt=\"\" class=\"wp-image-232\" width=\"400\" height=\"225\" loading=\"lazy\"><\/figure><div class=\"wp-block-group vf-in is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><small>Pressure reducing valves<\/small><b>Types of industrial pressure reducing valves<\/b><span>12 min read<\/span><\/p><\/div><p class=\"vf-enllac wp-block-paragraph\"><a class=\"vf-enllac-estirat\" href=\"\/en\/blog\/types-of-industrial-pressure-reducing-valves\/\" aria-label=\"Pressure reducing valves Types of industrial pressure reducing valves 12 min read\"><\/a><\/p><\/div><\/div><div class=\"wp-block-group vf-t-li is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group vf-amb-enllac is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wp-block-image vf-img-suelta\"><img decoding=\"async\" src=\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/portada_1_como-seleccionar-una-vlvula-de-control_Valfonta.jpg\" alt=\"\" class=\"wp-image-236\" width=\"400\" height=\"225\" loading=\"lazy\"><\/figure><div class=\"wp-block-group vf-in is-layout-flow wp-block-group-is-layout-flow\"><p class=\"vf-envolt wp-block-paragraph\"><small>Pressure reducing valves<\/small><b>What problems do pressure reducing valves commonly have?<\/b><span>6 min read<\/span><\/p><\/div><p class=\"vf-enllac wp-block-paragraph\"><a class=\"vf-enllac-estirat\" href=\"\/en\/blog\/pressure-reducing-valve-problems\/\" aria-label=\"Pressure reducing valves What problems do pressure reducing valves commonly have? 6 min read\"><\/a><\/p><\/div><\/div><\/div><\/section><section id=\"contactar\" 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\">Can we help with your installation?<\/h2><p class=\"wp-block-paragraph\">Tell us the fluid, the inlet and outlet pressures, the temperature, and the flow rate, and we will recommend the right valve.<\/p><p class=\"vf-pdp-contact wp-block-paragraph\">You can also call <a href=\"tel:+34933720888\">933 720 888<\/a> or email <a href=\"mailto:valfonta@valfonta.com\">valfonta@valfonta.com<\/a>.<\/p><\/div>\n<div class=\"wpcf7 no-js\" id=\"wpcf7-f535-o1\" lang=\"en-US\" dir=\"ltr\" data-wpcf7-id=\"535\">\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\/posts\/610#wpcf7-f535-o1\" method=\"post\" class=\"wpcf7-form init vf-form wpcf7-acceptance-as-validation\" aria-label=\"Contact form\" novalidate=\"novalidate\" data-status=\"init\" toolname=\"consulta_contacto\" tooldescription=\"Send an enquiry to Valfonta, industrial valve manufacturer; a member of the team will reply.\">\n<fieldset class=\"hidden-fields-container\"><input type=\"hidden\" name=\"_wpcf7\" value=\"535\" \/><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-f535-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=\"1792702971.1a766ca6d4e02a1f\" \/>\n<\/fieldset>\n<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><label class=\"vf-full\">Reason for your inquiry<span class=\"wpcf7-form-control-wrap\" data-name=\"motivo\"><select class=\"wpcf7-form-control wpcf7-select\" aria-invalid=\"false\" name=\"motivo\"><option value=\"\">Select<\/option><option value=\"Request a quote\">Request a quote<\/option><option value=\"Technical advice on choosing a valve\">Technical advice on choosing a valve<\/option><option value=\"Spare parts or repair\">Spare parts or repair<\/option><option value=\"Documentation or certificates\">Documentation or certificates<\/option><option value=\"Other\">Other<\/option><\/select><\/span><\/label><label class=\"vf-full\">Message *<span class=\"wpcf7-form-control-wrap\" data-name=\"mensaje\"><textarea cols=\"40\" rows=\"5\" maxlength=\"2000\" class=\"wpcf7-form-control wpcf7-textarea wpcf7-validates-as-required\" aria-required=\"true\" aria-invalid=\"false\" placeholder=\"Tell us what you need: fluid, pressures, flow rate, model, or serial number\u2026\" 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 message\" \/><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=\"#contactar\">Request a quote<\/a><\/p><\/div><\/article><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>Cavitation in a pressure reducing valve occurs when the pressure drops below the vapor pressure at the vena contracta and the bubbles collapse as the pressure recovers downstream, eroding the seat, plug, and body.<\/p>\n","protected":false},"author":1,"featured_media":225,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_generate-full-width-content":"true","_generate-disable-headline":"true","rank_math_title":"Reducing valve cavitation: causes and solutions | Valfonta","rank_math_description":"Noise and erosion in reducing valves: causes of cavitation, calculating the sigma coefficient, and Valfonta stainless steel solutions.","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. 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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\":\"WebPage\",\"@id\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/#webpage\",\"url\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/\",\"name\":\"Reducing valve cavitation: causes and solutions | Valfonta\",\"description\":\"Noise and erosion in reducing valves: causes of cavitation, calculating the sigma coefficient, and Valfonta stainless steel solutions.\",\"isPartOf\":{\"@id\":\"https:\/\/www.valfonta.com\/#website\"},\"about\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"inLanguage\":\"en\",\"datePublished\":\"2026-02-10T17:04:13+02:00\",\"dateModified\":\"2026-04-29T08:52:51+02:00\",\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/#breadcrumb\"}},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\",\"caption\":\"Cavitation in pressure reducing valves: causes, solutions, and recommendations\",\"inLanguage\":\"en\"},{\"@type\":\"ImageObject\",\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\",\"url\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\",\"width\":\"1000\",\"height\":\"1000\",\"caption\":\"cavitation in valves\",\"inLanguage\":\"en\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.valfonta.com\/en\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Blog\",\"item\":\"https:\/\/www.valfonta.com\/en\/blog\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Cavitation in pressure reducing valves: causes, solutions, and recommendations\",\"item\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/\"}]},{\"@type\":\"BlogPosting\",\"keywords\":\"Cavitation in valves\",\"datePublished\":\"2026-02-10T17:04:13+02:00\",\"dateModified\":\"2026-04-29T08:52:51+02:00\",\"articleSection\":\"Pressure reducing valves\",\"publisher\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"@id\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/#richSnippet\",\"isPartOf\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/#webpage\"},\"image\":{\"@id\":\"https:\/\/www.valfonta.com\/wp-content\/uploads\/2026\/10\/cavitacion-en-valvulas.webp\"},\"inLanguage\":\"en\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.valfonta.com\/en\/blog\/cavitation-in-valves\/#webpage\"},\"headline\":\"Cavitation in pressure reducing valves: causes, solutions, and recommendations\",\"name\":\"Reducing valve cavitation: causes and solutions | Valfonta\",\"description\":\"Noise and erosion in reducing valves: causes of cavitation, calculating the sigma coefficient, and Valfonta stainless steel solutions.\",\"author\":{\"@id\":\"https:\/\/www.valfonta.com\/#organization\"},\"abstract\":\"Cavitation in a pressure reducing valve occurs when the pressure drops below the vapor pressure at the vena contracta and the bubbles collapse as pressure recovers downstream, eroding the seat, plug, and body. It shows up as pitting, seat leakage, and a gravel-like noise. It is assessed with the sigma index (\u03c3): below 1.5, a standard globe valve cannot withstand it. It is corrected by sizing on Kv, with hardened Stellite internals, and by reducing the pressure in two or more stages.\"}]}]","footnotes":"","_vg_translation_of":"464","_vg_lang":"en","_vg_wpml_state":"{\"lang\":\"en\",\"trid\":\"626\",\"src\":\"es\"}"},"categories":[36],"tags":[],"class_list":["post-610","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pressure-reducing-valves"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/posts\/610","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/comments?post=610"}],"version-history":[{"count":3,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/posts\/610\/revisions"}],"predecessor-version":[{"id":10274,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/posts\/610\/revisions\/10274"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/media\/225"}],"wp:attachment":[{"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/media?parent=610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/categories?post=610"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.valfonta.com\/en\/wp-json\/wp\/v2\/tags?post=610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}