The Basic-Check valve is a versatile all-purpose, spring-assisted, in-line check valve that provides reliable, low maintenance service for a wide range of liquids and gases at various pressure/temperature combinations. The valve consists of a guard cage, spring, valve disc, retaining ring, and seat. It can be combined with pipe fittings such as reducing couplings, drain elbows, etc. to form a complete check valve unit ideally suited for a broad range of pipeline applications or incorporated into machinery for OEM applications. The metal-to-metal sealing area of the Basic-Check valve's disc and seat is precision lapped, providing very tight shut-off of both gas and liquid. If bubble-tight shut-off is required, resilient soft seats are available.