Mark 518 series0 pages

Pressure Regulators

Mark 518 Series
Low Pressure Back Pressure Regulators
The Mark 518 is a back pressure regulator for use
in low pressure air and gas services. With a selection of six pressure ranges, set points can be chosen to control back pressures from 1" w.c. to 7 psi
(3mbar to 9,5 bar). As a standard feature, the Mark
518 is provided with soft seats for ANSI Class VI
bubble-tight shutoff. The valve is also leak-proof
under vacuum conditions.

Operation

Application
The MK518 back pressure relief valve is used for
maintaining the pressure of air and gases in the
positive inches w.c. (mbar) pressure range. The
regulator is specifically designed for pressure
inertizing and blanketing in mixing vessels, storage tanks and containers using an inert gas such
as nitrogen.
For regulating back pressure under vacuum or for
use as a vacuum breaker, special configurations
of the Mark 518 are available. Additionally, an air
assisted version os available for higher setpoints
to aid tank pressurization during emptying with a
relief function.

Features
•t Completely self-operated –spring-loaded
regulator operates off of process pressure and
requires no external power source or air supply for operation.
•t Wide range of low pressure back pressure
settings – choose from six pressure ranges for
set points ranging from 1" w.c. to 200" w.c. (2
mbar to 520 mbar).
•t Long service life – all wetted metal parts produced from Stainless Steel or Hastelloy C for
durability and long life.
•t Tighter shutoff – soft seats for ANSI Class VI
bubble-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 518 Low Pressure Back Pressure Regulators

The spring in the Mark 518 holds the seat in the
normally closed position, As the inlet pressure
increases to the set point (as determined by the
value set via the adjusting screw), the diaphragm
is pushed upward to overcome the force of the
spring. When the pressure rises above the set
point, the valve will begin opening to relieve the
pressure. The pressure set point can be changed
by turning the adjusting screw clockwise or counter-clockwise to achieve the desired setting.