MK56 uses air (or gas) loaded on top of the diaphragm, instead of a conventional regulator where a spring applies the loading force that determines the set pressure. It has no spring or pilot and has the same rangeability (40:1) as a MK57, considered to be the most accurate regulator in the range.
By eliminating the spring, the regulator has almost no droop but the big advantage is being able to remotely control the set pressure and the wide pressure range that can be controlled. A conventional regulator might be able to regulate between 200-900 kpa but the MK56
could be loaded to provide upstream pressure control between a few kpa and then be adjusted right up to the maximum body pressure of the valve (890 psi for SS body). No spring changes..just adjust the pressure being loaded on the dome. The dome loading can be done by a loading station but the simplest method is just by using a JPR regulator from the Low Flow section or a conventional Air Filter Regulator. Adjust the regulator to a little over 5 kpa and the MK56 regulates the pressure to 5 kpa…..increase the air pressure to a little over 1200 kpa and the MK56 regulates to 1,200 kpa etc
* Options: Low flow trim, stainless teel, buna or viton diaphragm, BSPP, BSPT, NPT or flanged.