Watson McDaniel’s "O" Series pressure reducing valve offers a heavy-duty design, high precision, and superior downstream pressure stability for steam, gas, and liquid systems.
Key features of the "O" Series:
Robust and user-friendly construction: The unit utilizes a direct-acting mechanism with a rugged cast iron body, featuring a hardened 420 stainless steel disc and seat to minimize wear and damage.
High-pressure capability: Its sturdy construction ensures safe operation at maximum inlet pressures up to 17.3 barg (250 PSIG), with an adjustable outlet pressure range of 0.2 to 14 barg.
Integrated strainer: An internal strainer effectively prevents pipeline debris and impurities from reaching the valve's sealing surfaces.
Tight shut-off and stability: A precision-guided stem ensures stable outlet pressure despite fluctuations in inlet pressure.
Long service life: Hardened, wear-resistant disc and seat components maintain consistent pressure-regulating performance under harsh industrial conditions.
Compact design: Featuring standard NPT threaded connections and sizes ranging from 3/8 inch to 2 inches, the unit optimizes installation space for small heating equipment, humidifiers, and piping systems.
Type: O
Maximum inlet pressure: 17.3 barg
Minimum inlet pressure: 1 barg
Maximum inlet/outlet pressure differential: 8.6 barg
Minimum inlet/outlet pressure differential: 1 barg
Outlet pressure: 0.2 – 14 barg
Body material: Cast iron
Disc and seat material: 420 stainless steel
Connection: NPT threaded
Size: 3/8”, 1/2”, 3/4”, 1”, 1 1/4”, 1 1/2”, 2”
Valve structure:
Dimensions (mm):
| Size/Connection NPT |
Reduced Pressure Range (PSI) |
STEAM | Water • Oil • Air | Weight lbs |
| Model Code | Model Code | |||
| SINGLE SPRING | ||||
| 3/8” | 0-10 | O-11-N-13-B | O-11-N-13-V | 10 |
| Oct-50 | O-11-N-14-B | O-11-N-14-V | 10 | |
| 40-100 | O-11-N-09-B | O-11-N-09-V | 10 | |
| 100-200 | O-11-N-10-B | O-11-N-10-V | 10 | |
| 1/2” | 0-10 | O-12-N-13-B | O-12-N-13-V | 10 |
| Oct-50 | O-12-N-14-B | O-12-N-14-V | 10 | |
| 40-100 | O-12-N-09-B | O-12-N-09-V | 10 | |
| 100-200 | O-12-N-10-B | O-12-N-10-V | 10 | |
| 3/4” | 0-10 | O-13-N-13-B | O-13-N-13-V | 10 |
| Oct-50 | O-13-N-14-B | O-13-N-14-V | 10 | |
| 40-100 | O-13-N-09-B | O-13-N-09-V | 10 | |
| 100-200 | O-13-N-10-B | O-13-N-10-V | 10 | |
| 3/4” HC | 0-10 | OHC-13-N-0003-B | OHC-13-N-0003-V | 15 |
| Oct-30 | OHC-13-N-0004-B | OHC-13-N-0004-V | 15 | |
| 30-50 | OHC-13-N-0005-B | OHC-13-N-0005-V | 15 | |
| 40-85 | OHC-13-N-0006-B | OHC-13-N-0006-V | 15 | |
| 1” | 0-10 | O-14-N-0007-B | O-14-N-0007-V | 19 |
| Oct-30 | O-14-N-0008-B | O-14-N-0008-V | 19 | |
| 30-50 | O-14-N-0009-B | O-14-N-0009-V | 19 | |
| 40-85 | O-14-N-0010-B | O-14-N-0010-V | 19 | |
| 11/4” | 0-10 | O-15-N-0007-B | O-15-N-0007-V | 18 |
| 11232 | O-15-N-0008-B | O-15-N-0008-V | 18 | |
| 30-50 | O-15-N-0009-B | O-15-N-0009-V | 18 | |
| 40-85 | O-15-N-0010-B | O-15-N-0010-V | 18 | |
| 11/2” | 0-10 | O-16-N-0008-B | O-16-N-0008-V | 47 |
| Oct-30 | O-16-N-0009-B | O-16-N-0009-V | 47 | |
| 30-50 | O-16-N-0010-B | O-16-N-0010-V | 47 | |
| 40-85 | O-16-N-0011-B | O-16-N-0011-V | 47 | |
| 2” | 0-10 | O-17-N-0008-B | O-17-N-0008-V | 48 |
| Oct-30 | O-17-N-0009-B | O-17-N-0009-V | 48 | |
| 30-50 | O-17-N-0010-B | O-17-N-0010-V | 48 | |
| 40-85 | O-17-N-0011-B | O-17-N-0011-V | 48 | |
| DOUBLE SPRING | ||||
| 3/4” HC | 0-75 | OHC-13-N-0708-B | OHC-13-N-0708-V | 19 |
| 30-130 | OHC-13-N-0809-B | OHC-13-N-0809-V | 19 | |
| 1” | 0-75 | O-14-N-0809-B | O-14-N-0809-V | 22 |
| 30-130 | O-14-N-0910-B | O-14-N-0910-V | 22 | |
| 11/4” | 0-75 | O-15-N-0809-B | O-15-N-0809-V | 22 |
| 30-130 | O-15-N-0910-B | O-15-N-0910-V | 22 | |
| 11/2” | 0-75 | O-16-N-0809-B | O-16-N-0809-V | 48 |
| 30-130 | O-16-N-0910-B | O-16-N-0910-V | 48 | |
| 2” | 0-75 | O-17-N-0809-B | O-17-N-0809-V | 48 |
| 30-130 | O-17-N-0910-B | O-17-N-0910-V | 48 | |
Flow Rate Table:
Typical application:
TL Plus Engineering specializes in providing comprehensive solutions for saturated steam systems, covering everything from heating system calculations and piping and valve selection—tailored to specific temperature and pressure control applications—to ensuring safe and efficient system operation. The company also develops solutions to calculate and minimize energy losses in saturated steam systems.
Application of the Watson McDaniel O Pressure Reducing Valve for saturated steam systems.
TL Plus Engineering serves as the exclusive distributor and developer for Watson McDaniel’s US-manufactured valve product lines in the Vietnamese market.
