Review on NAVARME Non Return Check Valve Diesel Replacement Parts for Exhaust & Emissions by Cody Hunt

Bought for good reason as a check valve for my Audi Dual Boost on the intake manifold after the supercharger as part of the ventilation system. It failed at no more than 16psi and subsequently pressurized the crankcase and most likely sent the valve innards into my engine. I tried the second of 3 packs and the same thing happened like clockwork. I used a 21 year old OEM plastic check valve again in place of this junk, don't waste your money.