Description
Watson McDaniel 455 Series — Pressure Regulating Valve for Steam, Water, Other Liquids & Gases
The 455 Series is a direct-operated pressure regulating valve designed to reduce pressure in steam and liquid systems. It provides accurate pressure control with a simple, rugged design and requires only a 5 PSIG minimum inlet pressure. The 455 Series is ideally suited for steam systems that contain scale or other contaminants, making it a dependable solution for industrial and commercial applications.
The 455W Model is specifically designed for water and liquid service applications.
Product Overview
- Direct-operated design ensures stable downstream pressure control
- Suitable for Steam, Water, Air, and Other Liquid applications
- Compact and durable construction for extended service life
- Requires minimal inlet pressure — only 5 PSIG
- Excellent for use where scale or impurities are present in the system
Material Specifications
- Body (1/2″ – 4″): Cast Iron
- Valve Disc & Seat: Stainless Steel
- Diaphragm: Viton
Technical Specifications
- Available Sizes: 1/2″ – 4″
- Connections: NPT Threaded or Flanged (125#/250#)
- Maximum Inlet Pressure: 250 PSIG
- Minimum Inlet Pressure: 5 PSIG
- Maximum Outlet Pressure: 125 PSIG
- Minimum Differential Pressure: 20% of Inlet Pressure
Applications
- Steam Systems: For pressure reduction and stable control in heating and process steam lines
- Water & Liquid Systems (455W): For water, air, and other liquid flow control
- General Industrial Use: For air or gas service requiring consistent outlet pressure
Available Models — Steam Applications (455 Series)
| Size / Connection | Model Code | Body Material | Weight (lbs) |
|---|---|---|---|
| 1/2″ NPT | 455-12-N-X | SS | 15 |
| 3/4″ NPT | 455-13-N-X | SS | 15 |
| 1″ NPT | 455-14-N-X | SS | 18 |
| 1¼″ NPT | 455-15-N-X | SS | 18 |
| 1½″ NPT | 455-16-N-X | SS | 18 |
| 2″ NPT | 455-17-N-X | SS | 29 |
| 1½″ 150# FLG | 455-17-F150-X | Cast Iron | 41 |
| 2″ 300# FLG | 455-17-F300-X | Cast Iron | 45 |
| 2½″ 250# FLG | 455-18-F250-X | Cast Iron | 105 |
| 2½″ 125# FLG | 455-19-F125-X | Cast Iron | 125 |
| 3″ 250# FLG | 455-19-F250-X | Cast Iron | 125 |
| 4″ 125# FLG | 455-20-F125-X | Cast Iron | 175 |
| 4″ 250# FLG | 455-20-F250-X | Cast Iron | 175 |
Available Models — Water Applications (455W Series)
| Size / Connection | Model Code | Body Material | Weight (lbs) |
|---|---|---|---|
| 1/2″ NPT | 455W-12-N-X | SS | 15 |
| 3/4″ NPT | 455W-13-N-X | SS | 15 |
| 1″ NPT | 455W-14-N-X | SS | 15 |
| 1¼″ NPT | 455W-15-N-X | SS | 18 |
| 1½″ NPT | 455W-16-N-X | SS | 18 |
| 2″ NPT | 455W-17-N-X | SS | 29 |
| 1½″ 150# FLG | 455W-17-F150-X | Cast Iron | 75 |
| 2″ 300# FLG | 455W-17-F300-X | Cast Iron | 75 |
| 2½″ 125# FLG | 455W-18-F125-X | Cast Iron | 105 |
| 2½″ 250# FLG | 455W-19-F125-X | Cast Iron | 125 |
| 3″ 250# FLG | 455W-19-F250-X | Cast Iron | 125 |
| 4″ 125# FLG | 455W-20-F125-X | Cast Iron | 175 |
| 4″ 250# FLG | 455W-20-F250-X | Cast Iron | 175 |
Spring Selection Guide
Select the proper spring code (X) based on outlet pressure range:
| Reduced Pressure Range (PSIG) | Spring Color | Code (X) |
|---|---|---|
| 5–15 | Red | 63 |
| 10–35 | Blue | 64 |
| 30–75 | Yellow | 65 |
| 70–125 | Green | 72 |
Example Model Codes
- 455-15-N-65: 1¼″ NPT, 30–75 PSIG outlet pressure (Steam Application)
- 455W-18-F125-73: 2½″ 125# Flanged, 40–70 PSIG outlet pressure (Water Application)
Important Notes
- Flange selection may reduce pressure/temperature ratings.
- Use appropriate spring code when ordering based on required outlet pressure range.
- 455 Series for Steam Applications; 455W Series for Water and Liquid Applications.
Note: All prices are indicative and subject to change. Consult Watson McDaniel or authorized distributors for detailed technical data and configuration options.