Your cart is empty
Browse our catalog to find the parts you need.
These images are illustrative and may not match the product exactly. Always verify by part number — or confirm instantly with the assistant using a photo or VIN.
PAI Industries · Air System
LSV-5238
In stock · ships from Knoxville
This is an ST-4 style air safety valve (also called a pop-off valve) designed to protect a truck's air compressor system from over-pressurization.
Confirm the part fits before you buy. Applications and interchange numbers are researched and audited per part.
Verified fitment for 3 applications
Add your truck to see whether it's one of them
All confirmed applications for this part number.
Mack Trucks
Other applications
Mack Trucks
Other applications
Referenced as a component on select Mack applications with Tu-Flo 550/750 compressors. May fit other makes using the same compressor series, but always verify against the OEM part number before purchasing.
Part data verified against 5 catalog sources
Numbers this part supersedes or interchanges with. Showing 16 of 18.
Different year, make, or config? Get a confirmation against your truck in under a minute.
It screws directly into the compressor head and is set to automatically crack open and vent air if system pressure exceeds 250 PSI, preventing damage to the compressor and air lines. You typically replace it when the old valve is leaking, stuck open, or failed closed, which can lead to dangerous pressure buildup. It's commonly used on heavy-duty trucks with Bendix Tu-Flo 550 or 750 series air compressors.
Part Number: LSV-5238
SAFTEY VALVE 250PSI
Vendor: PAI Industries
Dealer: Knox Trailers
Compatibility, alternatives, and more
Parts commonly needed alongside air system
