MK66 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 MK67, 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 have a reduced pressure range of say 14-40 kpa and might neeed several spring changes to achive 400 kpa or 1,000 kpa.
The MK66 could be air loaded to provide a reduced pressure of anywhere between a few kpa and right up to the maximum body pressure of the valve (890 psi for SS body). 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 14 kpa and the MK66 regulates the pressure to 14 kpa…..increase the air pressure to a little over 300 kpa and the MK66 regulates to 300 kpa etc
* Options: Low flow trim, stainless teel, buna or viton diaphragm, BSPP, BSPT, NPT or flanged