Os&y Rising Stem Valve

Overview

OS&Y (Outside Screw and Yoke) Rising Stem Valves are widely used gate valves in fire protection systems, designed to control water flow with a clear visual indication of valve position. The rising stem design allows operators to easily determine whether the valve is in the open or closed position.

Operating Principle (As Provided)

In OS&Y gate valves, the stem is located outside the valve body and moves upward or downward as the valve opens or closes. When the valve is open, the stem rises; when closed, the stem lowers. This external movement provides immediate visual confirmation of valve status.

Rising Stem Valve Design (As Provided)

Rising stem valves operate by pushing or pulling the valve stem. Gate valves and globe valves are the most common examples of rising stem valve designs used in fire protection and industrial applications.

Use in Fire Protection Systems (As Provided)

OS&Y gate valves are used as cut-off and zone control valves in fire protection systems and are often selected as an alternative to supervisory switched butterfly valves. Due to their visible stem movement, these valves are easy to monitor and inspect.

Installation & Visibility (As Provided)

To enhance visibility and traceability within the system, OS&Y valves may be used with post indicators instead of handwheels. Valve operation can be controlled via these indicators, and the open or closed position can be clearly identified. OS&Y valves are suitable for both indoor and outdoor installations.

Advantages & Disadvantages (As Provided)

• Advantages: Smaller than pressure cut and pressure reducing valves, more economical than many alternative valve types, and provides clear visual indication.
• Disadvantages: Larger than some other fire protection valves and generally less economical compared to compact valve designs.

Connection Types (As Provided)

• Threaded connection
• Flanged connection
• Grooved connection

Technical Specifications (As Provided)

• Working Pressure: 175 psi – 350 psi
• Maximum Working Temperature: 0.6°C – 52°C
• Available Dimensions: 1” – 16”

Material Features (As Provided)

• Body: ASTM A536 Nodular Cast Iron
• Cover: ASTM A536 Nodular Cast Iron
• Spindle: ASTM AISI 420 Stainless Steel
• Slide: EPDM covered nodular cast iron
• Gasket: EPDM
• O-Ring: EPDM

Application Areas (As Provided)

OS&Y rising stem valves can be used in most fire protection systems and are commonly installed near water tanks and at the suction or discharge sides of fire pumps. However, there is no mandatory requirement to use OS&Y gate valves specifically on pump lines.

Approvals & Certifications (As Provided)

• UL Listed
• ULc Listed
• FM Approved

Operational Benefits

• Clear visual indication of valve position
• Reliable shut-off and zone control
• Suitable for indoor and outdoor fire systems
• Durable construction for long service life
• Compliance with international fire protection standards