O-Series Regulator
The O-Series direct-operated pressure regulators with heavy duty cast iron bodies and internal strainer are suitable for a wide range of applications in the
low-to-moderate flow range. Applications include small heaters, humidifiers, various hospital equipment, tire molds, as well as many other general uses.
Controlling Pressure
The O-Series valve reduces downstream pressure of steam, water, or gas.
Downstream pressure is set by turning an adjustment screw that increases or
decreases spring force above a diaphragm. The downstream pressure applies an
upward force to the diaphram to compress the adjustment spring. When the
system pressure equals the set point, the diaphragm moves upward against the
adjustment spring force, closing the valve.
Design Features
The O-Series contains hardened stainless steel seat and disc with a guided stem
for extended service life. An internal strainer protects against dirt and scale.
A phosphor Bronze diaphragm (Model Code B) specifically designed for steam
service is a preferred choice over a stainless steel diaphragm which are prone to
work hardening. Phosphor Bronze diaphragms are for steam use only and may
fracture if used on liquid service.
Viton diaphragms (Model code V) are specifically designed for water, air, or other
liquid service and have a working temperature range up to 300ºF.
Pressure Adjustment Range
When selecting any regulator the proper control spring must be selected so the valve may be properly adjusted to the desired outlet pressure.
- The DOUBLE pressure adjustment spring option gives the user a wider adjustable pressure range which may be desirable in some applications.
- The smallest size O-Valve (3/4”, 1/2”, 3/4”) use the same body and seat; are only available with a SINGLE pressure adjustment spring option.
- The larger size O-valves, which include the 3/4“ HC thru the 2” bodies have four distinct pressure range when using the SINGLE
pressure adjustment spring option and two wider pressure ranges when using the DOUBLE pressure adjustment spring option.
Other Considerations
The limitation of the direct-operated type regulator is a variation of up to 10%
of initial set pressure depending on changes in flow through the valve. As flow
requirements through the valve increase, the outlet set pressure will tend to
decrease.
For example; Inlet pressure is 100 PSIG and downstream pressure is adjusted to
maintain 50 PSIG while 250 lbs/hr of steam flows through the valve. If the steam
flow rate happens to increase to 500 lbs/hr, then the outlet pressure would drop
to 45 PSIG.