{"title":"Trapped Pressure Unloaders","description":"\u003ch2\u003eTrapped Pressure Unloaders for Pressure Washers\u003c\/h2\u003e\n\n\u003cp\u003eRegulate pressure and protect your pump with professional trapped pressure unloaders designed for commercial pressure washing applications. Our selection includes General Pump, Comet, and other trusted brands in multiple flow rates and pressure ratings from 2900 to 8000 PSI.\u003c\/p\u003e\n\n\u003ch3\u003eHigh-Flow Trapped Pressure Unloaders\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eComet VHP51 Unloader:\u003c\/strong\u003e 26.4 GPM capacity at 8000 PSI max, 194°F max temp with 1\/2\" F connections\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVRT100 Green Spring Unloader:\u003c\/strong\u003e 26.4 GPM max flow, 4500 PSI max pressure, 194°F max temp with 1\/2\" FPT connections\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZH288 Blue Spring Unloader:\u003c\/strong\u003e 21 GPM max flow, 4500 PSI max pressure, 195°F max temp with improved design and reduced pressure loss\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYVB4021B Unloader:\u003c\/strong\u003e 21 GPM @ 4050 PSI with regulating multi-gun capability\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eStandard Flow Trapped Pressure Unloaders\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVR54 Unloader:\u003c\/strong\u003e 8 GPM at 2900 PSI, 194°F max temp with 3\/8\" MPT inlet\/discharge and 3\/8\" FPT bypass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact Design:\u003c\/strong\u003e Suitable for smaller pressure washers and portable units\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eEasy Start Unloaders\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVRT3-310EZ Black Spring Unloader:\u003c\/strong\u003e Pressure actuated unloader with built-in easy start valve, rated for 4500 PSI\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEasy Start Feature:\u003c\/strong\u003e Built-in valve reduces starting pressure for easier pull starts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperator Convenience:\u003c\/strong\u003e Eliminates need for separate easy start valve\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUnloader Repair Kits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVRT3-310 Repair Kit:\u003c\/strong\u003e Complete replacement parts kit for VRT3-310 unloader models\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtend Service Life:\u003c\/strong\u003e Rebuild unloaders instead of replacing entire units\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCost-Effective Maintenance:\u003c\/strong\u003e Repair kits cost far less than new unloaders\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat Are Trapped Pressure Unloaders?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure Regulation:\u003c\/strong\u003e Maintain consistent pressure when trigger gun is released\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrapped Pressure Design:\u003c\/strong\u003e Keep system pressurized when gun is closed for instant response\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBypass Operation:\u003c\/strong\u003e Divert water flow back to pump inlet when gun is closed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure Adjustment:\u003c\/strong\u003e Adjustable spring tension allows pressure tuning\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-Gun Capability:\u003c\/strong\u003e Some models support multiple operators with regulating features\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Use Trapped Pressure Unloaders?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstant Response:\u003c\/strong\u003e System stays pressurized for immediate spray when trigger is pulled\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump Protection:\u003c\/strong\u003e Prevent pump damage from deadheading and pressure spikes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConsistent Pressure:\u003c\/strong\u003e Maintain steady operating pressure throughout the job\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProfessional Performance:\u003c\/strong\u003e Essential component for commercial pressure washing operations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature Protection:\u003c\/strong\u003e Bypass flow prevents excessive heat buildup in pump\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eChoosing the Right Trapped Pressure Unloader\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlow Rating:\u003c\/strong\u003e Match unloader GPM rating to your pump's flow capacity (8-26.4 GPM)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure Rating:\u003c\/strong\u003e Ensure unloader is rated for your system's maximum PSI (2900-8000 PSI)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection Size:\u003c\/strong\u003e Verify thread sizes match your pump and plumbing (3\/8\" or 1\/2\")\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature Rating:\u003c\/strong\u003e Confirm unloader handles your water temperature (194-195°F typical)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecial Features:\u003c\/strong\u003e Consider easy start valves or multi-gun capability if needed\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eInstallation \u0026amp; Adjustment\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProper Mounting:\u003c\/strong\u003e Install unloader on pump outlet or high-pressure manifold\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBypass Routing:\u003c\/strong\u003e Route bypass line back to pump inlet or water supply\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure Adjustment:\u003c\/strong\u003e Turn adjustment screw to set desired operating pressure\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Operation:\u003c\/strong\u003e Verify unloader bypasses smoothly when trigger gun is released\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRegular Maintenance:\u003c\/strong\u003e Inspect and clean unloader periodically for reliable operation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWhether you're running a high-flow commercial pressure washer or a compact portable unit, trapped pressure unloaders provide the pressure regulation and pump protection professional operations demand. From the Comet VHP51 rated for 8000 PSI to compact VR54 models for smaller systems, every unloader is designed to maintain consistent pressure and protect your pump from damage. Easy start models like the VRT3-310EZ reduce starting effort, while multi-gun capable unloaders support multiple operators. We stock unloaders for every flow rate and pressure rating plus repair kits to keep your existing unloaders running reliably.\u003c\/p\u003e\n\n\u003cp\u003eNeed other pressure washer parts? Browse our \u003ca href=\"\/collections\/unloader-valves\" title=\"Unloader Valves\"\u003eall unloader valves\u003c\/a\u003e, \u003ca href=\"\/collections\/pump-parts\" title=\"Pump Parts\"\u003epump parts\u003c\/a\u003e, \u003ca href=\"\/collections\/thermal-relief-valves\" title=\"Thermal Relief Valves\"\u003ethermal relief valves\u003c\/a\u003e, and \u003ca href=\"\/collections\/all-products\" title=\"All Products\"\u003ecomplete product catalog\u003c\/a\u003e.\u003c\/p\u003e","products":[{"product_id":"repair-kit-for-vrt3-310-unloader","title":"REPAIR KIT FOR VRT3-310 UNLOADER","description":"\u003cp\u003eREPAIR KIT FOR VRT3-310 UNLOADER\u003c\/p\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":48412883550505,"sku":"5137","price":21.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/file_2bf51b9c-43e9-4aa3-8940-808eb4f1c1dd.jpg?v=1714668540"},{"product_id":"vr54-unloader-8gpm-2900-psi-4072000041","title":"VR54 UNLOADER 8GPM 2900 PSI 4072000041","description":"\u003cb\u003ePressure actuated unloader\u003c\/b\u003e\u003cp style=\"color:rgb(0,0,0);\"\u003e\u003cb\u003eFEATURES:\u003c\/b\u003e\u003c\/p\u003e\u003cp style=\"color:rgb(0,0,0);\"\u003e\u003cbr\u003e\u003c\/p\u003e\u003cul style=\"color:rgb(0,0,0);\"\u003e \u003cli\u003eReplaces MV520\u003c\/li\u003e \u003cli\u003eHexagonal check valve for smoother flow\u003c\/li\u003e \u003cli\u003eReinforced new body with hexagon wrench grip in bypass area\u003c\/li\u003e \u003cli\u003eEasy maintenance: the pressure regulating unit is fully removable from above\u003c\/li\u003e \u003cli\u003eAdjustment ring nut\u003c\/li\u003e \u003cli\u003eErgonomic plastic adjustment knob\u003c\/li\u003e \u003cli\u003eSame repair kit as the MV520 and MV540\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e​\u003cb\u003eSPECIFICATIONS:\u003c\/b\u003e\u003cp style=\"color:rgb(0,0,0);\"\u003e\u003cbr\u003e\u003c\/p\u003e\u003cul style=\"color:rgb(0,0,0);\"\u003e \u003cli\u003eMaximum flow: 8 GPM\u003c\/li\u003e \u003cli\u003eMaximum pressure: 2900 PSI\u003c\/li\u003e \u003cli\u003eMaximum temperature: 194F\u003c\/li\u003e \u003cli\u003eInlet port 3\/8\" MPT\u003c\/li\u003e \u003cli\u003edischarge port: 3\/8\" MPT\u003c\/li\u003e \u003cli\u003eBypass port: 3\/8\" FPT\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":48412967600425,"sku":"6961","price":63.3,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/file_38ee2977-9d7c-4f40-a298-3063ef5ea4d2.jpg?v=1714669019"},{"product_id":"vrt3-310ez-blk-sprng-unloader-4072000002-4500-psi","title":"VRT3-310EZ Black Spring Unloader","description":"\u003cp\u003e\u003cb\u003ePressure actuated unloader with built-in easy start valve\u003c\/b\u003e\u003c\/p\u003e\u003cp\u003eVRT3-310EZ BLK SPRING UNLOADER 4072000002 4500 PSI\u003c\/p\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":52188365717801,"sku":"VRT3-310EZ","price":61.16,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/file_92263b54-edda-4cbf-be3e-0a373757ed5a.jpg?v=1714669108"},{"product_id":"zh288-blue-spring-unloader-yub","title":"ZH288 Blue Spring Unloader YUB","description":"\u003cp\u003eZH288 Blue Spring Unloader 1\/2\" NPT\u003c\/p\u003e\n\u003cp\u003eYUB \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFEATURES:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eImproved design, trapped pressure unloader\u003c\/li\u003e\n\u003cli\u003eReduced pressure loss\u003c\/li\u003e\n\u003cli\u003eExtremely reliable\u003c\/li\u003e\n\u003cli\u003eEasy maintenance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003cstrong\u003eSPECIFICATIONS:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMaximum volume: 21 GPM\u003c\/li\u003e\n\u003cli\u003eMaximum pressure: 4500 PSI\u003c\/li\u003e\n\u003cli\u003eMaximum temperature: 195F. The valve is designed for continuous use at a water temperature of 140F. It can operate for short periods at a maximum temperature of 195F.\u003c\/li\u003e\n\u003cli\u003eInlet: Dual 1\/2\" FPT\u003c\/li\u003e\n\u003cli\u003eDischarge: 1\/2\" FPT\u003c\/li\u003e\n\u003cli\u003eBypass: 1\/2\" FPT\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis product is intended to be incorporated on a finished machine. This product is to be used with clean fresh water, for use involving different or corrosive liquids, contact the GP Customer Service Department. Appropriate filtration should be installed when using impure liquids. Choose the valve\u003cbr\u003eappropriate to the working data of the pump (permissible pressure, flow and rated temperature of the system). The pressure of the pump must not exceed the maximum pressure of the valve.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eOPERATION\u003cbr\u003eThe valve regulates the maximum pressure of the system by varying the flow discharged by the bypass. The adjustment is made by altering, by\u003cbr\u003emeans of a piston, the position of a sphere which partially closes the bypass opening. The valve is sensitive to water flow. At gun opening, the water\u003cbr\u003eflows through the valve which maintains the system in pressure until the gun closes, the interruption of the flow provokes the complete aperture of\u003cbr\u003ethe bypass which allows to discharge the flow at low pressure. At gun closure, the special mechanism of zero setting, which does not include a check\u003cbr\u003evalve, keeps in connection the delivery line and the bypass line, in that way permitting to lower the pressure all around the system and not only in the\u003cbr\u003esource line of the valve.\u003c\/p\u003e\n\u003cp\u003eINSTALLATION\u003cbr\u003eThis valve, on a system that produces hot water, must be fitted upstream from the source of heat. On a system that generates hot water, it is advisable to use accessories that limit the accidental increase of fluid temperature. Always install a safety valve. We recommend the use of a nozzle with flow rate which allows a regular discharge from the valve bypass of at least 5% of the flow supplied by the pump. In order to achieve a constant pressure\u003cbr\u003eand easy adjustment. If the nozzle wears out, the pressure decreases. To reset pressure back to working level, it is necessary to replace the worn nozzle. When a new nozzle is fitted, resetting of the system to its original working pressure is required.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eDISCHARGE SYSTEM AND WATER ADDUCTION\u003cbr\u003eThe bypass discharge can be sent back to the pump intake or returned into a tank; in such cases it is advisable that the tank be fitted with baffles to reduce eventual turbulence and air bubbles which could be harmful to the pump.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003ePRESSURE ADJUSTMENT\/CALIBRATION\u003cbr\u003eThe desired working pressure must be adjusted with the system running and the gun opened. Adjust the pressure by screwing or unscrewing the adjustment knob. The operation is easier if the correct nozzle has been chosen (see above). When screwing the adjustment nut a consequent pressure increase must be matched. If, before reaching the desired pressure, there is no pressure increase, DO NOT FORCE. Rather, check the correct ratio of nozzle\/flow rate - pressure and, if necessary, replace with a smaller size nozzle.\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eATTENTION: the nut in position 24 is a mechanical security device that limits the maximum pressure; it must absolutely NOT be removed.\u003c\/p\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":48413045063977,"sku":"6965","price":156.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/file_9d96a359-5b62-439d-986d-1f1bf5476c81.jpg?v=1714669562"},{"product_id":"vrt100-green-spring-unloader-1-2in","title":"VRT100 Green Spring Unloader 1\/2in","description":"\u003cp\u003eVRT 100 UNLOADER\u003c\/p\u003e\u003cp\u003eVRT100 Green Spring 1\/2 in Unloader\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eSpecs:\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eMax Flow 26.4 GPM\u003c\/p\u003e\u003cp\u003eMax Temp 194°F\u003c\/p\u003e\u003cp\u003eConnection 1\/2\" FPT Inlet x Outlet \u0026amp; By-Pass\u003c\/p\u003e\u003cp\u003e \u003c\/p\u003e\u003cp\u003e11152 Part Number MPWSR\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eManatee Pressure Washer Supply and Repair\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e\"More than just the tip\"\u003c\/p\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":48413045326121,"sku":"11152","price":145.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/file_c731aeb1-c60a-4bea-886a-79b62783bb08.jpg?v=1714669564"},{"product_id":"26-4gpm-8000psi-unloader-194f-1-2-2-bypassports","title":"Comet VHP51 Unloader 26.4GPM 8000PSI","description":"\u003cp\u003eComet VHP51 Unloader\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e26.4GPM\u003c\/li\u003e\n\u003cli\u003e8000PSI\u003c\/li\u003e\n\u003cli\u003e194F\u003c\/li\u003e\n\u003cli\u003eInlet: 1\/2\" F\u003c\/li\u003e\n\u003cli\u003eOutlet: 1\/2\" F\u003c\/li\u003e\n\u003cli\u003eBypass: 1\/2\" F\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":48413289873705,"sku":"VHP51","price":292.02,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/Screenshot_2025-07-03_112715.png?v=1751556524"},{"product_id":"product_1c9bb75c-b40d-4d0b-a7da-8b00fab47059","title":"YVB4021B","description":"\u003cp\u003eUnloader, Pressure Trapping, 21.GPM @ 4050 PSI (Regulating Multi Gun)\u003c\/p\u003e","brand":"MPWSR","offers":[{"title":"Default Title","offer_id":48581993103657,"sku":"YVB4021B","price":156.43,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/files\/background-editor_output_31d0d3c1-6039-4ff1-9d85-af358067cc89.png?v=1721144087"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0861\/6070\/3785\/collections\/background-editor_output_31d0d3c1-6039-4ff1-9d85-af358067cc89.png?v=1770321635","url":"https:\/\/mpwsr.com\/collections\/trapped-pressure-unloaders.oembed","provider":"MPWSR x APE","version":"1.0","type":"link"}