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Operating Condition
Steam Load  
OSS-Series (for Steam)
This is the OSS-Series for Steam applications. For Gas or Liquid applications or for more information, please see the OSS-Series main section.

Steam: The OSS Series, with Stainless Steel CF8M body and Hardened 420 Stainless Steel seat, is suitable for a wide range of applications in the low-to-moderate flow range.

Size Connection Inlet Pressure Range (PSIG) Max Capacity
1/2" - 1 1/4"  NPT 15-250 Steam - 2,141 lbs/hr.
ModelSizeTypeSpring TypeReduced Pressure Range (psig)Max Inlet Pressure (psig)Capacity (lb/h)
OSS-12-N-10-S1/2"NPTSingle100 - 200250
OSS-12-N-13-S1/2"NPTSingle0 - 10250
OSS-12-N-14-S1/2"NPTSingle10 - 50250
OSS-13-N-13-S3/4"NPTSingle0 - 10250
OSS-14-N-0007-S1"NPTSingle0 - 10250
OSS-15-N-0008-S1 1/4"NPTSingle10 - 30250
OSS-15-N-0009-S1 1/4"NPTSingle30 - 50250
OSS-13-N-10-S3/4"NPTSingle100 - 200250
OSS-15-N-0010-S1 1/4"NPTSingle40 - 85250
OSS-12-N-09-S1/2"NPTSingle40 - 100250
OSS-13-N-14-S3/4"NPTSingle10 - 50250
OSS-14-N-0009-S1"NPTSingle30 - 50250
OSS-14-N-0010-S1"NPTSingle40 - 85250
OSS-15-N-0007-S1 1/4"NPTSingle0 - 10250
OSS-13-N-09-S3/4"NPTSingle40 - 100250
OSS-14-N-0008-S1"NPTSingle10 - 30250
Product Overview
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. This style of regulator does not require an external sensing line. Set pressure is controlled by turning an adjustment screw with lock nut that increases or decreases spring force above the diaphragm. Several spring ranges are available, depending upon the downstream pressure that needs to be maintained. O-Series contains hardened stainless steel seat and disc for extended service life. Phosphor Bronze Diaphragm specifically designed for Steam service is considered a preferred choice over Stainless Steel diaphragms which are prone to work-hardening and potential cracking. Viton diaphragms are specifically designed for water, air, gases and other liquid service and have a working temperature range up to 300°F.
• Hardened stainless steel seat and disc for extended service life (55 Rc)
• Phosphor Bronze diaphragm for Steam Service
• Viton diaphragm for up to 300ºF for Water, Oil & Air Service
• Double spring available for extended outlet pressure range
•Integral stainless steel strainer on 3/4” HC, 1”, 1-1/4”, 1-1/2” & 2”
Selection / Sizing / Capacities
From the Capacity chart, find the inlet pressure and required regulator outlet pressure. Follow across chart to nearest capacity (steam, air, water) that meets or slightly exceeds demand requirements. Follow vertically up to determine appropriate size. When exact application values are not shown, interpolate between values. Select a model with the spring range that accommodates the required outlet set pressure.

Application: 200 lbs/hr of 100 PSIG Steam reduced to 30 PSIG
Model Code: O-12-N-14-B (1/2” O-Series, 10-50 PSIG spring range, NPT with Bronze Diaphragm for Steam)

** 3/4" HC is high-capacity version of standard 3/4" valve.

Dimension and Weights