{"product_id":"industrial-131b-pilot-unloader-valve","title":"Industrial 131B Pilot Unloader Valve","description":"\u003cdiv\u003eRolair 131B Pilot Unloader Valve is a replaceable component used on Rolair 4090HK17 portable air compressors to automatically vent the unloading line and prevent unnecessary startup cycling when demand drops. The valve operates as a piloted unloader: as air is used and downstream pressure falls to the load setting, the pilot opens to depressurize the line, then closes to hold the compressor in the unloaded state until demand rises again. In the 4090HK17 configuration (which uses a K17 pump), the 131B is listed in Rolair’s parts diagrams as the Pilot Unloader Valve, confirming its role in the machine’s automatic unloading sequence. The part provides a 1\/4-inch tube connection and a 1\/4-inch MPT pilot port, aligning with common Rolair tubing and pilot-line fittings. Retailers frequently catalog the 131B as the standard replacement pilot unloader valve for Rolair gas models and for electric constant-run units, underscoring its status as the go-to component for restoring proper unloading behavior without replacing larger assemblies. This makes the 131B a precise, compatible choice for maintenance or repair of Rolair systems that rely on an automatic unloading valve to control run time and cycling.\u003c\/div\u003e","brand":"ROLAIR","offers":[{"title":"New","offer_id":46284224757994,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0716\/8039\/3450\/files\/GTG-STOCK-022.png?v=1788727428","url":"https:\/\/gtghardware.com\/products\/industrial-131b-pilot-unloader-valve","provider":"GTG Hardware","version":"1.0","type":"link"}