{"id":3184,"date":"2026-07-08T10:29:03","date_gmt":"2026-07-08T02:29:03","guid":{"rendered":"https:\/\/prancehydraulic.com\/blog\/hydraulic-cast-iron-gear-pump-guide\/"},"modified":"2026-07-21T17:43:35","modified_gmt":"2026-07-21T09:43:35","slug":"hydraulic-cast-iron-gear-pump-guide","status":"publish","type":"post","link":"https:\/\/prancehydraulic.com\/de\/blog\/hydraulic-cast-iron-gear-pump-guide\/","title":{"rendered":"Hydraulic Cast Iron Gear Pump: Working Principle, Specs &#038; Applications"},"content":{"rendered":"<div class=\"b2b-article\" style=\"max-width: 820px; margin: 0 auto;\">\n<p style=\"margin: 0 0 16px; line-height: 1.7;\"><strong>Hydraulic Cast Iron Gear pump<\/strong> \u2014 Cast iron hydraulic gear pumps use positive displacement gear meshing to move fluid in mobile and industrial circuits where rugged housings and moderate-to-high pressure are required. This guide focuses on hydraulic sizing, application fit, and procurement documentation for export and industrial buyers. Cross-check public data on prancehydraulic.com and confirm project limits with your design engineer.<\/p>\n<nav style=\"background: #f7f9fb; border: 1px solid #e3e8ee; border-radius: 8px; padding: 14px 18px; margin: 0 0 24px;\">\n<p style=\"margin: 0 0 16px; line-height: 1.7;\"><strong>On this page<\/strong><\/p>\n<ul style=\"margin: 0 0 18px 1.2em; line-height: 1.7;\">\n<li style=\"margin: 0 0 16px; line-height: 1.7;\"><a href=\"#part-1-core-concepts-and-working-principle\">Part 1. Core Concepts and Working Principle<\/a><\/li>\n<li style=\"margin: 0 0 16px; line-height: 1.7;\"><a href=\"#part-2-specifications-limits-and-selection-crite\">Part 2. Specifications, Limits, and Selection Criteria<\/a><\/li>\n<li style=\"margin: 0 0 16px; line-height: 1.7;\"><a href=\"#part-3-field-application-and-installation-notes\">Part 3. Field Application and Installation Notes<\/a><\/li>\n<li style=\"margin: 0 0 16px; line-height: 1.7;\"><a href=\"#part-4-documentation-and-handover-checklist\">Part 4. Documentation and Handover Checklist<\/a><\/li>\n<li style=\"margin: 0 0 16px; line-height: 1.7;\"><a href=\"#part-5-commissioning-monitoring-and-long-term-op\">Part 5. Commissioning, Monitoring, and Long-Term Operations<\/a><\/li>\n<\/ul>\n<\/nav>\n<figure style=\"margin: 26px 0; text-align: center;\"><img loading=\"lazy\" decoding=\"async\" style=\"max-width: 640px; width: 100%; height: auto; display: block; margin: 0 auto; border-radius: 8px;\" src=\"https:\/\/prancehydraulic.com\/wp-content\/uploads\/2026\/07\/hydraulic-cast-iron-gear-pump-guide-body-3.webp\" alt=\"Hydraulic Cast Iron Gear pump \u2014 Prance Hydraulic official product with illustrative industrial background (not a real site photo)\" width=\"640\" height=\"360\" \/><\/figure>\n<h2 id=\"part-1-core-concepts-and-working-principle\" style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">Part 1. Core Concepts and Working Principle<\/h2>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">This section explains how hydraulic cast iron gear pump fits in open-circuit and industrial hydraulic systems as a positive-displacement component.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Buyers should confirm displacement, rated pressure, speed limits, and fluid compatibility before comparing quotations.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Misalignment between catalog peaks and actual duty cycle is a common source of overheating, noise, and early wear.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Size displacement from required flow at actual shaft speed: Q \u2248 displacement \u00d7 speed \u00d7 volumetric efficiency factor.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Confirm inlet conditions\u2014line size, height, temperature, and fluid viscosity at cold start\u2014not only steady-state catalog data.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Cross-check <a href=\"https:\/\/prancehydraulic.com\/product\/external-gear-pump-hdh\/\">Prance Hydraulic product line<\/a> against your circuit pressure, relief setting, and filtration plan.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">For export machines, confirm port standards (SAE\/ISO), rotation, and shaft type before issuing PO.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Include duty pressure, flow, fluid type, ambient temperature, and duty cycle in every RFQ.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Confirm imperial and metric port and shaft dimensions for export machines before fabrication.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Define warranty response, spare parts lead time, and who performs startup in the purchase order.<\/p>\n<div class=\"tip-box\" style=\"border-left: 4px solid #2e7d32; background: #f3faf4; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Tip:<\/strong> Request duty-point data sheets, not marketing summaries alone.<\/div>\n<h2 id=\"part-2-specifications-limits-and-selection-crite\" style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">Part 2. Specifications, Limits, and Selection Criteria<\/h2>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Continuous versus intermittent pressure ratings must match your relief valve setting and load cycle.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Inlet conditions, filtration (ISO 4406), and fluid viscosity at cold start affect both performance and service life.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Mounting, shaft, rotation, and port orientation should be frozen before mechanical design sign-off.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Case drain lines on piston units must return to tank without excessive backpressure; plug unused ports per manufacturer guidance.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Parallel pump circuits need isolation and load-sharing review to avoid fighting or overheating.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Heat exchangers or tank volume may be required when duty cycle is high\u2014do not size tank from catalog defaults alone.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Use <a href=\"https:\/\/prancehydraulic.com\/hydraulic-solutions\/\">hydraulic solutions<\/a> pages for integrated system questions that span pump, valve, and motor selection.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Include duty pressure, flow, fluid type, ambient temperature, and duty cycle in every RFQ.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Confirm imperial and metric port and shaft dimensions for export machines before fabrication.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Define warranty response, spare parts lead time, and who performs startup in the purchase order.<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 0 0 20px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Parameter<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">What to verify<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Typical source<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Pressure \/ flow<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Duty point vs continuous rating<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Manufacturer curve<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Speed range<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Motor\/pump RPM limits<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Datasheet<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Fluid \/ temperature<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Viscosity window<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">O&amp;M manual<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Filtration<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Inlet cleanliness target<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">ISO 4406 \/ OEM spec<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<figure style=\"margin: 26px 0; text-align: center;\"><\/figure>\n<div class=\"warning-box\" style=\"border-left: 4px solid #f9a825; background: #fffbf0; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Important:<\/strong> Do not operate hydraulic pumps or motors without adequate inlet supply and relief protection\u2014cavitation and over-pressure cause rapid wear and safety hazards.<\/div>\n<h2 id=\"part-3-field-application-and-installation-notes\" style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">Part 3. Field Application and Installation Notes<\/h2>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">On site, Hydraulic Cast Iron Gear pump selection must match actual piping, tank, and relief architecture\u2014not spreadsheet assumptions alone.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Verify rotation, mounting torque, and port orientation before first pressurization.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Inlet vacuum and return backpressure limits are common root causes of premature failure.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Document startup pressure, temperature, and case drain (if applicable) at acceptance.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">After startup, log pressure, flow, case drain, and temperature at working load for baseline troubleshooting.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Seal and bearing wear often appears as noise, heat, or rising case drain before total loss of function.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Submit non-catalog duty points via <a href=\"https:\/\/prancehydraulic.com\/contact-us\/\">Prance Hydraulic engineering contact<\/a> for application review.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Keep fluid analysis on a schedule when contamination or water ingress is possible.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Include duty pressure, flow, fluid type, ambient temperature, and duty cycle in every RFQ.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Confirm imperial and metric port and shaft dimensions for export machines before fabrication.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Define warranty response, spare parts lead time, and who performs startup in the purchase order.<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 0 0 20px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Check item<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Why it matters<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Typical owner<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Inlet \/ return line size<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Prevents cavitation and overheating<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Hydraulic designer<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Relief setting vs component rating<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Prevents over-pressure damage<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Commissioning<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Filtration beta ratio<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Protects clearances<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Maintenance<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">As-built schematic<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Supports future service<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Owner O&amp;M<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"tip-box\" style=\"border-left: 4px solid #2e7d32; background: #f3faf4; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Tip:<\/strong> Photograph nameplates and port labels during acceptance\u2014they are required for correct spare parts.<\/div>\n<div class=\"tip-box\" style=\"border-left: 4px solid #2e7d32; background: #f3faf4; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Tip:<\/strong> Archive baseline pressure, flow, and temperature readings after commissioning.<\/div>\n<h2 id=\"part-4-documentation-and-handover-checklist\" style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">Part 4. Documentation and Handover Checklist<\/h2>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Industrial acceptance relies on documented ratings and test evidence\u2014not verbal assurances.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Use the tables below as a hydraulic RFQ and handover starting point; your EPC contract may require more.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Cross-check <a href=\"https:\/\/prancehydraulic.com\/product\/external-gear-pump-hdh\/\">related Prance Hydraulic product pages<\/a> for public specifications and request gaps in writing.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Normalize Incoterms, warranty, and commissioning scope when comparing suppliers.<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 0 0 20px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Document \/ item<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Purpose<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">When to request<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Performance \/ displacement curve<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Verify flow at speed and pressure<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Before purchase order<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Mounting \/ shaft \/ port drawing<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Mechanical and piping design<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Design phase<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Filtration and fluid spec<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Prevent premature wear<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Before first fill<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Spare seal \/ kit list<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Lifecycle planning<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Contract negotiation<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Commissioning checklist<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Acceptance at duty point<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Before handover<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width: 100%; border-collapse: collapse; margin: 0 0 20px;\">\n<thead>\n<tr>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Application<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Typical component<\/th>\n<th style=\"border: 1px solid #d9e1e8; padding: 9px 12px; background: #f4f7fa; text-align: left;\">Selection note<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Mobile construction auxiliaries<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Gear or piston pump<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Confirm pressure, speed, and tank size<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Industrial power unit<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Gear, vane, or piston pump<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Match displacement to motor RPM and relief setting<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Crane \/ drill rig drives<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Piston motor (e.g. A6VM class)<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Check case drain and speed limits<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Wheel \/ conveyor drive<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Orbit motor<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Size displacement for torque at low speed<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Direction \/ proportional control<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Solenoid or proportional valve<\/td>\n<td style=\"border: 1px solid #d9e1e8; padding: 9px 12px; vertical-align: top;\">Match flow, pressure drop, and electrical interface<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"tip-box\" style=\"border-left: 4px solid #2e7d32; background: #f3faf4; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Tip:<\/strong> Store factory test reports with the component serial number.<\/div>\n<div class=\"tip-box\" style=\"border-left: 4px solid #2e7d32; background: #f3faf4; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Tip:<\/strong> Keep fluid analysis reports with the machine maintenance file.<\/div>\n<h2 id=\"part-5-commissioning-monitoring-and-long-term-op\" style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">Part 5. Commissioning, Monitoring, and Long-Term Operations<\/h2>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Commissioning should verify performance at working pressure and speed, not only correct rotation direction.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Log baseline pressure, temperature, case drain (if fitted), and noise at acceptance load.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Train maintenance on lockout\/tagout, filter change intervals, and fluid sampling procedures.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Trend case drain and temperature in service\u2014step changes often precede seal or bearing failure.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">After circuit modifications, re-verify relief settings and hose ratings before returning to production.<\/p>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Keep spare seal kits and critical filters based on lead time and downtime cost.<\/p>\n<div class=\"tip-box\" style=\"border-left: 4px solid #2e7d32; background: #f3faf4; padding: 12px 16px; margin: 0 0 18px; line-height: 1.7;\"><strong>Tip:<\/strong> Re-sample fluid after the first 100 hours if the system was flushed at commissioning.<\/div>\n<h2 style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">Recommended Prance Hydraulic Products<\/h2>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">For project support, explore our <a href=\"https:\/\/prancehydraulic.com\/product\/external-gear-pump-hdh\/\">related product line<\/a>, <a href=\"https:\/\/prancehydraulic.com\/hydraulic-solutions\/\">solution options<\/a>, and <a href=\"https:\/\/prancehydraulic.com\/about-us\/\">OEM\/ODM capabilities<\/a> on prancehydraulic.com.<\/p>\n<figure style=\"margin: 26px 0; text-align: center;\"><img loading=\"lazy\" decoding=\"async\" style=\"max-width: 640px; width: 100%; height: auto; display: block; margin: 0 auto; border-radius: 8px;\" src=\"https:\/\/prancehydraulic.com\/wp-content\/uploads\/2026\/07\/hydraulic-cast-iron-gear-pump-guide-product-3.webp\" alt=\"Prance Hydraulic gear \u2014 official product photo with illustrative scene background (not a real site photo)\" width=\"640\" height=\"360\" \/><\/figure>\n<h2 style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">FAQ<\/h2>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">What is a cast iron hydraulic gear pump?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">It is a positive-displacement pump with cast iron housing and meshing gears that move a fixed volume of hydraulic fluid each revolution.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">How does a hydraulic gear pump work?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Gear teeth separate at the inlet to draw fluid in, carry it around the housing, and force it out at the outlet as teeth mesh again.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">What pressure can a cast iron gear pump handle?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Many industrial and mobile cast iron designs are specified in roughly 200\u2013300 bar (about 2900\u20134350 psi); confirm continuous vs peak ratings on the datasheet.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">What is the difference between external and internal gear pumps?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">External gear pumps use two external gears; internal designs use a crescent partition and often run quieter with good high-viscosity suction performance.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">Where are cast iron gear pumps used?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Common uses include construction and agricultural auxiliaries, industrial power units, lubrication circuits, and moderate-pressure transfer lines.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">How do you size a hydraulic gear pump?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Calculate required flow from displacement \u00d7 shaft speed, then verify pressure rating, inlet conditions, fluid viscosity, and filtration match the duty cycle.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">Why use cast iron instead of aluminum for gear pumps?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Cast iron adds rigidity and damping under cyclic pressure; aluminum may be lighter but is selected when weight matters and duty is less severe.<\/p>\n<h3 style=\"margin: 28px 0 10px; font-size: 1.15em; line-height: 1.35;\">What filtration is required for hydraulic gear pumps?<\/h3>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\">Manufacturer literature often references ISO 4406 cleanliness around 18\/16\/13 at the pump inlet\u2014finer filtration generally extends gear and bearing life.<\/p>\n<h2 style=\"margin: 42px 0 14px; font-size: 1.35em; line-height: 1.3;\">References<\/h2>\n<ul style=\"margin: 0 0 18px 1.2em; line-height: 1.7;\">\n<li><a href=\"https:\/\/www.michael-smith-engineers.co.uk\/resources\/useful-info\/gear-pumps\" rel=\"nofollow noopener\" target=\"_blank\">Michael Smith Engineers \u2014 Gear Pumps<\/a><\/li>\n<li><a href=\"https:\/\/powersource.danfoss.com\/products\/pumps\/mobile-pumps\/gear-pumps\/rugid-cast-iron-gear-pumps?tab=overview\" rel=\"nofollow noopener\" target=\"_blank\">Danfoss PowerSource \u2014 Rugid cast iron gear pumps<\/a><\/li>\n<li><a href=\"https:\/\/assets.danfoss.com\/documents\/238589\/AI299873918277en-000103.pdf\" rel=\"nofollow noopener\" target=\"_blank\">Danfoss XD Series datasheet<\/a><\/li>\n<li><a href=\"https:\/\/prancehydraulic.com\/product\/external-gear-pump-hdh\/\" rel=\"nofollow noopener\">Prance External Gear Pump HDH<\/a><\/li>\n<\/ul>\n<p style=\"margin: 0 0 16px; line-height: 1.7;\"><strong>Ready to discuss your project?<\/strong> Contact <a href=\"https:\/\/prancehydraulic.com\/contact-us\/\">Prance Hydraulic engineering support<\/a> with your project parameters and technical requirements.<\/p>\n<\/div>\n<p><script type=\"application\/ld+json\">{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What is a cast iron hydraulic gear pump?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It is a positive-displacement pump with cast iron housing and meshing gears that move a fixed volume of hydraulic fluid each revolution.\"}}, {\"@type\": \"Question\", \"name\": \"How does a hydraulic gear pump work?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Gear teeth separate at the inlet to draw fluid in, carry it around the housing, and force it out at the outlet as teeth mesh again.\"}}, {\"@type\": \"Question\", \"name\": \"What pressure can a cast iron gear pump handle?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Many industrial and mobile cast iron designs are specified in roughly 200\u2013300 bar (about 2900\u20134350 psi); 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Third-party trademarks are referenced for compatibility search purposes only.<\/em><\/p>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Learn how cast iron hydraulic gear pumps work, typical 200\u2013300 bar ratings, sizing tips, and applications in construction, agriculture, and industrial circuits.<\/p>","protected":false},"author":5,"featured_media":3349,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3184","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/posts\/3184","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/comments?post=3184"}],"version-history":[{"count":10,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/posts\/3184\/revisions"}],"predecessor-version":[{"id":3493,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/posts\/3184\/revisions\/3493"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/media\/3349"}],"wp:attachment":[{"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/media?parent=3184"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/categories?post=3184"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prancehydraulic.com\/de\/wp-json\/wp\/v2\/tags?post=3184"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}