Mini Regulator Drain Check (MRDC)
by Nelson

The Mini Regulator Drain Check (MRDC) provides excellent pressure regulation and drain check capabilities in one compact unit — even as an integral component in a swing assembly. This offers numerous advantages including the ability to use non-regulated / less expensive pop-up bodies. Offering a flow range from 0.15 - 5 GPM with 1/2" thread connections, the MRDC is the ideal solution to maintain constant pressure and prevent wasteful and undesirable low-head drainage.
 
Pressure Options Available: 20, 30, 35, 40, 45, 50 psi
Recommended Flow Range: 0.15 GPM to 5 GPM
Maximum Inlet Pressure: 150 PSI
Minimum Inlet Pressure: 5 PSI above regulator pressure

How it works: The MRDC is a normally closed device. The check will not open until a certain minimum inlet pressure is reached. The minimum pressure to open an MRDC is approximately 75% of nominal pressure. Provide 5 PSI above the nominal pressure for the most accurate pressure regulation.

The MRDC is not designed for operation below freezing temperatures. System drainage and air winterization is recommended to prevent damage to the system. Adequate air capacity and pressure are necessary to air winterize all regulators and sprinklers within a zone. For specific information on air winterization please contact the factory. Walla Walla Sprinkler Company Pressure Regulators are accurate to 6% of the manufacturer’s coefficient of variation.
Caution! Pressure regulators should be installed downstream from all shut-off valves.