Mark 50 Series0 pages

Back Pressure Regulatorst

Mark 50 Series
Self-Operated Back Pressure Regulators
The Mark 50 Sliding Gate Back Pressure Regulator
is used to regulate upstream pressure at a predetermined setpoint. The spring in the Mark 50 holds the
sliding gate seats in their normally closed position.

This brochure includes the following Series:
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MK50: a line of self-operating back pressure regulators designed with Jordan Valve’s sliding gate
seats.
MK51: The MK51 features a larger diaphragm
than a standard MK50 to provide even greater
sensitivity and more accurate regulation of your
required setpoint.
MK50QC: The MK50QC features a “Quick
Change” dome for simple range spring replacements. Ideal for facilities with multiple back pressure requirements as it is possible to stock one
valve with several spare springs to cover a wide
range of needs.
MK50H: The MK50H features a handwheel that
is mounted on the adjusting screw to allow easy
setpoint changes.
MK50HP: The MK50HP option is an elongated
spring housing that features a large spring for
high pressure setpoints up to 450 psi (31,03
bar).
MK50GP: The MK50GP option is used in grain
processing for starch cookers and other viscous
services.
MK50CR: The MK50CR option has a special
spring housing for use if the valve is in cryogenic
services.
MK501/502: The MK501 and MK502 meet higher
capacity requirements than standard back pressure regulators.

Mark 50 Features
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Sliding Gate Trim — unique seat design for unsurpassed trim life and accuracy.
Jorcote Seat Coating — ceramic composite for
liquids, gases and especially steam. Very low
friction with outstanding wear resistance and a
temperature rating of up to 550°F (288°C). Steam
tested to 1,000,000 cycles and still maintained
Class IV leakage.
Jorlon Diaphragm — extremely durable, virtually
universally applicable up to 450°F. Tested without
failure to over 1,000,000 full stroke cycles. Ideal
for steam, gases and liquids. 316SST diaphragm
applicable up to 650°F.
Straight-through Flow — The flow is straight
through the valve seats and body. Direction of the
disc travel is perpendicular to the flow, not opposed to the direction of the flow. Thus, the flow
does not unbalance the seats. The MK50 can use
a wider range of its stroke to give accurate control; less offset and rangeability up to 20:1.
Quiet Operation — typically 5-10 dB less than
conventional globe style regulators. The disc
and plate are always in contact, which eliminates
chattering. Straight-through flow minimizes turbulence. Multiple orifices in the plate and disc divide
the flow stream into smaller flow components.
Minimum Maintenance — The MK50 sliding
gate seats require no special tools for disassembly. The seats are pre-lapped at the factory and
are self-lapping while in operation ensuring a
continual tight shutoff.
Jordan Valve, a division of Richards Industries
3170 Wasson Road • Cincinnati, OH 45209
513.533.5600 • 800.543.7311 • 513.871.0105 (f)
info@richardsind.com • www.jordanvalve.com

Mark 50 Self-Operated Back Pressure Regulators

The upstream pressure is sensed beneath the diaphragm. (A sensing line is required on sizes:
2-1/2", 3", and 4"). As the upstream pressure exceeds
the setpoint, pressure is exerted on the diaphragm
which raises the stem to modulate the disc (the movable component of the sliding gate seat set) toward the
open position. As the seats open, upstream pressure
will be regulated to the required setpoint. A decrease
in pressure relaxes the spring and diaphragm to move
the seats toward the closed position.