{"id":100131,"date":"2026-02-15T20:19:25","date_gmt":"2026-02-15T20:19:25","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100131"},"modified":"2026-07-12T13:23:10","modified_gmt":"2026-07-12T13:23:10","slug":"hydraulic-accumulator-calculator","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/uk\/calculators\/hydraulic-accumulator-calculator\/","title":{"rendered":"Documented Accumulator Gas-Volume Screening Calculator"},"content":{"rendered":"\r\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Documented Ideal-Gas Accumulator Volume Screening Calculator\",\"description\":\"Calculate ideal precharge gas volume for a documented accumulator cycle using absolute pressures and a sourced isothermal or single polytropic exponent.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/hydraulic-accumulator-calculator\/\",\"applicationCategory\":\"Engineering 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.15s}.vc-related-link:hover{border-color:var(--vc-accent);color:var(--vc-accent);background:var(--vc-accent-light)}.vc-promo{margin-top:24px;padding:20px;background:linear-gradient(135deg,var(--vc-accent-light),var(--vc-surface));border:1px solid var(--vc-border);border-radius:var(--vc-radius-lg);display:flex;align-items:center;gap:16px}.vc-promo-text{flex:1;font-size:14px;color:var(--vc-ink-secondary)}.vc-promo-text strong{color:var(--vc-ink)}.vc-promo-link{padding:8px 20px;font-size:13px;font-weight:700;color:#fff;background:var(--vc-accent);border-radius:var(--vc-radius);text-decoration:none;white-space:nowrap;transition:background .15s}.vc-promo-link:hover{background:var(--vc-accent-hover)}.vc-footer{text-align:center;padding:32px 16px;font-size:13px;color:var(--vc-ink-muted)}.vc-footer a{color:var(--vc-accent);text-decoration:none}.vc-footer a:hover{text-decoration:underline}.vc-footer-links{margin-top:8px;font-size:12px}.vc-footer-links a{margin:0 8px}@media print{.vc-section-body{max-height:none!important}.vc-faq-a{max-height:none!important}.vc-results{max-height:none!important;padding:24px!important}.vc-copy-btn,.vc-section-chevron,.vc-faq-chevron,.vc-presets,.vc-promo{display:none!important}}.vc-doc-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.vc-wide{grid-column:1\/-1}.vc-result-note{font-size:13px;color:var(--vc-ink-secondary);margin:0}@media(max-width:600px){.vc-doc-grid{grid-template-columns:1fr}.vc-wide{grid-column:auto}}.vc-doc-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.vc-wide{grid-column:1\/-1}.vc-formula-box{font-family:var(--vc-mono);background:var(--vc-surface-alt);border:1px solid var(--vc-border-light);border-radius:6px;padding:14px;margin:12px 0;line-height:1.75}.vc-result-note{font-size:13px;color:var(--vc-ink-secondary);margin:0}.vc-hidden{display:none!important}@media(max-width:650px){.vc-doc-grid{grid-template-columns:1fr}.vc-wide{grid-column:auto}}<\/style>\r\n<div class=\"vc-calculator\" id=\"vc-accumulator\"><header class=\"vc-header\"><p class=\"vc-header-eyebrow\">Absolute-pressure single-exponent ideal-gas screening<\/p><h1 class=\"vc-header-title\">Documented Accumulator Gas-Volume Screening Calculator<\/h1><p class=\"vc-header-subtitle\">Calculate the ideal precharge gas volume and gas states for one documented liquid-delivery cycle. All three pressures must be absolute and temperature-normalized for the selected calculation basis.<\/p><div class=\"vc-badges\"><span class=\"vc-badge\">Absolute pressure only<\/span><span class=\"vc-badge\">Sourced exponent n<\/span><span class=\"vc-badge\">Not nominal product selection<\/span><\/div><\/header>\r\n<div class=\"vc-card\"><form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\"><div class=\"vc-doc-grid\"><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-id\">Calculation \/ project identifier<\/label><input class=\"vc-input\" id=\"vc-id\" type=\"text\" maxlength=\"220\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-product\">Accumulator type\/product and manufacturer sizing source<\/label><input class=\"vc-input\" id=\"vc-product\" type=\"text\" maxlength=\"500\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-punit\">Absolute pressure unit for p0, p1 and p2<\/label><select class=\"vc-select\" id=\"vc-punit\"><option value=\"\">Select\u2026<\/option><option value=\"bar\">bar(a)<\/option><option value=\"kpa\">kPa(a)<\/option><option value=\"mpa\">MPa(a)<\/option><option value=\"psi\">psi(a)<\/option><\/select><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-p0\">Corrected gas precharge p0 <span class=\"vc-label-hint\">(absolute)<\/span><\/label><input class=\"vc-input\" id=\"vc-p0\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-p1\">Minimum operating pressure p1 <span class=\"vc-label-hint\">(absolute)<\/span><\/label><input class=\"vc-input\" id=\"vc-p1\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-p2\">Maximum operating pressure p2 <span class=\"vc-label-hint\">(absolute)<\/span><\/label><input class=\"vc-input\" id=\"vc-p2\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field vc-wide\"><label class=\"vc-label\" for=\"vc-pbasis\">Pressure reference, atmospheric conversion and precharge-temperature correction source \/ revision<\/label><input class=\"vc-input\" id=\"vc-pbasis\" type=\"text\" maxlength=\"600\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-dv\">Required delivered liquid volume \u0394V<\/label><input class=\"vc-input\" id=\"vc-dv\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-vunit\">Liquid-volume unit<\/label><select class=\"vc-select\" id=\"vc-vunit\"><option value=\"\">Select\u2026<\/option><option value=\"l\">litre (L)<\/option><option value=\"m3\">cubic metre (m\u00b3)<\/option><option value=\"usgal\">US liquid gallon (US gal)<\/option><\/select><\/div><div class=\"vc-field vc-wide\"><label class=\"vc-label\" for=\"vc-dv-source\">Delivered-volume requirement and cycle source \/ revision<\/label><input class=\"vc-input\" id=\"vc-dv-source\" type=\"text\" maxlength=\"500\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-model\">Gas process model<\/label><select class=\"vc-select\" id=\"vc-model\"><option value=\"\">Select\u2026<\/option><option value=\"iso\">Isothermal ideal gas: n=1<\/option><option value=\"poly\">Documented single polytropic exponent n<\/option><\/select><\/div><div class=\"vc-field\" id=\"vc-n-field\"><label class=\"vc-label\" for=\"vc-n\">Documented polytropic exponent n<\/label><input class=\"vc-input\" id=\"vc-n\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field vc-wide\"><label class=\"vc-label\" for=\"vc-n-source\">Exponent, charge\/discharge duration and thermal-process source<\/label><input class=\"vc-input\" id=\"vc-n-source\" type=\"text\" maxlength=\"600\"><\/div><div class=\"vc-field vc-wide\"><label class=\"vc-label\" for=\"vc-gas-source\">Gas identity, charge temperature and gas-state source<\/label><input class=\"vc-input\" id=\"vc-gas-source\" type=\"text\" maxlength=\"600\"><\/div><div class=\"vc-field vc-wide\"><label class=\"vc-label\" for=\"vc-real-source\">Real-gas and manufacturer correction disposition<\/label><input class=\"vc-input\" id=\"vc-real-source\" type=\"text\" maxlength=\"600\"><\/div><div class=\"vc-field vc-wide\"><label class=\"vc-label\" for=\"vc-validity\">Selected product limits, shell\/dead-volume and application safety review<\/label><input class=\"vc-input\" id=\"vc-validity\" type=\"text\" maxlength=\"700\"><\/div><\/div><p id=\"vc-error\" role=\"alert\" style=\"margin:.75rem 0 0;color:#b42318\"><\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Applicability gate:<\/strong> this is a single-exponent ideal-gas volume screen. It assumes one gas mass and p0V0^n=p1V1^n=p2V2^n for the documented states. It does not calculate temperature correction, real-gas factors, different charge\/discharge exponents, dead volume, bladder\/piston limits, transient flow, heat transfer, surge\/pulsation response or a catalogue nominal size.<\/p><\/div><\/form>\r\n<div class=\"vc-results\" id=\"vc-results\" aria-live=\"polite\"><div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Documented ideal-gas screening result<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">Copy<\/button><\/div><div class=\"vc-result-grid\"><div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\">Ideal precharge gas volume V0<\/div><div class=\"vc-rcard-value\" id=\"vc-r-v0\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">V0 converted to litres<\/div><div class=\"vc-rcard-value\" id=\"vc-r-v0l\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Gas volume V1 at minimum pressure<\/div><div class=\"vc-rcard-value\" id=\"vc-r-v1\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Gas volume V2 at maximum pressure<\/div><div class=\"vc-rcard-value\" id=\"vc-r-v2\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Ideal oil fill V0\u2212V1 at p1<\/div><div class=\"vc-rcard-value\" id=\"vc-r-oil1\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Ideal oil fill V0\u2212V2 at p2<\/div><div class=\"vc-rcard-value\" id=\"vc-r-oil2\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Delivered-volume check V1\u2212V2<\/div><div class=\"vc-rcard-value\" id=\"vc-r-check\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Precharge ratio p0\/p1<\/div><div class=\"vc-rcard-value\" id=\"vc-r-ratio\">\u2014<\/div><\/div><\/div><p class=\"vc-result-note\" id=\"vc-r-note\"><\/p><\/div><\/div>\r\n<div class=\"vc-section vc-open\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Equations, sources and strict boundary<\/span><\/span><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\"><h3>Implemented single-exponent model<\/h3><div class=\"vc-formula-box\">p0,abs V0^n = p1,abs V1^n = p2,abs V2^n<br>V1 = V0(p0\/p1)^(1\/n)<br>V2 = V0(p0\/p2)^(1\/n)<br>\u0394V = V1\u2212V2<br>V0 = \u0394V \/ [(p0\/p1)^(1\/n) \u2212 (p0\/p2)^(1\/n)]<\/div><p>Only ratios of pressures appear, but every pressure must be absolute. A gauge value must first be converted with a documented atmospheric\/reference pressure in the same unit. The page never assumes that bar(g) equals bar(a) or that a fixed atmospheric offset is correct for every site\/reference.<\/p><h3>Process exponent and temperature<\/h3><p>Isothermal operation uses n=1. A polytropic value, including 1.4 for a justified rapid nitrogen idealization, must be entered with its product\/cycle source. This page does not decide n from an arbitrary time threshold and does not apply precharge-temperature or real-gas corrections.<\/p><h3>Manufacturer reference and published example<\/h3><p>The <a href=\"https:\/\/betterfit-us.hydac.com\/wp-content\/uploads\/Accumulators.pdf\" target=\"_blank\" rel=\"noopener\">HYDAC accumulator catalogue<\/a> publishes the same ideal-gas equation, distinguishes isothermal\/polytropic\/adiabatic cases, requires temperature and real-gas corrections, and gives an example with p0=1245 psi, p1=1500 psi, p2=3000 psi, \u0394V=1.35 US gal and n=1.4. The displayed equation gives V0=3.949314 US gal, reproducing the catalogue\u2019s rounded ideal result of 3.95 US gal before its 1.16 real-gas correction and nominal-size selection. The <a href=\"https:\/\/www.parker.com\/parkerimages\/ACCUMULATOR\/CAT\/ENGLISH\/1630007.pdf\" target=\"_blank\" rel=\"noopener\">Parker HY10-1630\/US sizing guide<\/a> explicitly defines its sizing pressures in PSIA, uses application\/time\/temperature-dependent gas coefficients and warns that temperature variation affects precharge.<\/p><h3>Standards boundary<\/h3><p><a href=\"https:\/\/www.iso.org\/standard\/44781.html\" target=\"_blank\" rel=\"noopener\">ISO 4413:2010<\/a>, edition 3, Published and confirmed in 2021, specifies general rules and safety requirements for hydraulic systems. Its public abstract does not establish this sizing equation, exponent or precharge percentage; this page therefore does not call the arithmetic an ISO formula or claim ISO 4413 compliance. The inventory token \u201cISO 70\u201d was a false positive caused by a former numeric preset beginning with 70, not a cited standard.<\/p><h3>Why the former page was changed<\/h3><p>The former inputs were merely labelled \u201cbar,\u201d inviting gauge-pressure entry into an absolute-pressure gas law. It silently chose n=1 or 1.4 from broad speed labels, published unsupported one-minute thresholds and universal 90\/95% precharge rules, inserted presets\/defaults and labelled the ideal V0 as the required accumulator volume without real-gas, temperature, product or reserve corrections.<\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Stored-energy hazard:<\/strong> this result is not authorization to select, charge, isolate or service an accumulator. Follow the exact manufacturer procedure and applicable law\/standard. Parker\u2019s guide states that accumulator circuits should automatically unload stored pressure when machinery shuts down. Verify rated pressure\/temperature, compatible gas and elastomers, isolation, relief, discharge control, inspection and trained-personnel requirements.<\/p><\/div><\/div><\/div><\/div><footer class=\"vc-footer\"><p>\u00a9 2024\u20132026 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a><\/p><p>Documented ideal-gas volume screening only. Scientific review: July 2026.<\/p><\/footer><\/div>\r\n<script>(function(){'use strict';function $(id){return document.getElementById(id)}var map={ac_id:'vc-id',ac_product:'vc-product',ac_punit:'vc-punit',ac_p0:'vc-p0',ac_p1:'vc-p1',ac_p2:'vc-p2',ac_pbasis:'vc-pbasis',ac_dv:'vc-dv',ac_vunit:'vc-vunit',ac_dv_source:'vc-dv-source',ac_model:'vc-model',ac_n:'vc-n',ac_n_source:'vc-n-source',ac_gas_source:'vc-gas-source',ac_real_source:'vc-real-source',ac_validity:'vc-validity'};var pf={bar:100,kpa:1,mpa:1000,psi:6.894757293168361},vf={l:1,m3:1000,usgal:3.785411784},vlabel={l:'L',m3:'m\u00b3',usgal:'US gal'},plabel={bar:'bar(a)',kpa:'kPa(a)',mpa:'MPa(a)',psi:'psi(a)'};function num(raw){var s=String(raw).trim().replace(',','.');if(s.length>80||!\/^[-+]?(?:\\d+(?:\\.\\d*)?|\\.\\d+)(?:[eE][+-]?\\d+)?$\/.test(s))return NaN;return Number(s)}function fmt(v){if(!Number.isFinite(v))return'\u2014';if(Object.is(v,-0)||v===0)return'0';return Number(v.toPrecision(12)).toString()}function 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