Magnetic Check Valve

The MCV series is a magnetic check valve: the disc is held closed by a magnet rather than a spring, and lifts as soon as the pressure difference reverses. The absence of a spring is the point - there is no cracking pressure to overcome, so the valve opens at very small differentials and closes again as soon as flow stops, which is exactly what a check valve on a liquid or discharge line needs.

Fourteen sizes run from 1/4 inch to 1-5/8 inch, with Kv values from 0.47 to 27.78 m3/h. Maximum working pressure is 3,000 to 5,500 kPa depending on size, and the internal mesh is 40 - coarse enough not to act as a strainer, fine enough to keep braze scale off the seat.

Typical positions are the discharge line of a parallel compressor set (to stop gas flowing back through a stopped compressor), the liquid line of a pump-down circuit, and the outlet of a hot gas bypass line. In each case the valve enforces one direction of flow, and the low opening differential matters most on the discharge side where the available difference is small.

Installation is directional, usually horizontal with the arrow following flow; vertical installation with upward flow is possible but should be checked for the size in question. The valve is not a substitute for a solenoid - it closes on flow reversal, not on command.

For selection match the line size, then check the Kv against expected flow: an oversized check valve chatters at low flow, and a chattering valve destroys its own seat within a season.