ORV Series
Liquid and Gas Service Proportional Relief Valves
Features
■ Set pressures from 10 to 6000 psig (0.68 to 413 bar)
■ 1/4 and 1/2 in. and 6 to 12 mm end connections.
■ SS316 atainless steel construction.
ORV3 Series Low-Pressure Valves
■ Service up to 300 psig (20.6 bar)
■ One spring for the full set pressure range: 10 to 225 psig (0.68 to 15.5 bar)
■ Orifie: 4.8 mm (0.19 in.)
■ 1/4 in. and 6- and 8-mm end connections - ORV3A series
■ 1/2 in. and 12 mm end connections - ORV3B series
ORV6 Series High-Pressure Valves
■ Service up to 6000 psig (413 bar)
■ Multiple springs for a selection of set pressure ranges
■ Orifie: 3.4 mm (0.19 in.)
■ 1/4 in. and 6- and 8-mm end connections - ORV6A series
■ 1/2 in. and 12 mm end connections - ORV6B series
Applications
ORV series relief Valves are designed to protect gaiges, instruments, and devices from over-pressure.
Valves are proportional relief valves that open gradually as the pressure increases. Consequently, they do not have a capacity rating at a given pressure rise (accumulation). they are not certified to ASME or any other codes.
- Caution
Some system applications require relief valves to meet specific safety codes. The system designer and user must determine when such codes apply and whether these relief valves conform to them.
Operation
ORV Series relief valves OPEN when system pressure reaches the set pressure and CLOSE when system pressure falls below the set pressure.
Valves are designed to open at pre-set pressire and direct fluids through the outlet port that discharges to a diff erent location in the system.
Valve mounting position is vertical with the cap on top.
■ High-pressure ORV6 series-select and install the spring that covers the required set pressure; apply the matching label to the cap.
■ Low-pressure ORV3 series-the spring is already installed.
-For valves not actuated for a period of time, initial relief pressure may be higher than the set pressure.
Technical Data
Seal Material Temperature Ratings
■ FKM seal is standard.
Pressure-Temperature Ratings
The temperature rating of Stainless-Steel ORV Series valves is -40 to 148°C (-40 to 300°F).
When combining seal material, the temperature rating of the seal may become the limiting factor on the valve's temperature rating.
Set Pressure (Cracking Pressure)
Set pressure is the upstream pressure at which the first indication of flow occurs. Set pressure of each valve after initial relidf is repeatable within ± 5 % at room temperature.
Optional Set- Pressure at Factory
To set valve to a specific cracking pressure at factory, select valve ordering number, specify the spring designator and the desired set-perssure either in bar or in psig in the valve ordering number. Example: ORV6-A6T-RS2-50BAR-SS
The valves are set at factory for the desired cracking pressure and supplied with wire clamped; locknut locked out, labeled, and marking indicating the set pressure on the body.
Resealing Pressure
Valves are resealed by the spring force when the inlet cracking pressure falls down below the set pressure.
Resealing pressure is the ustream pressure at which there is no indication of flow. Resealing pressure is always lower than set pressure.
Refer to Table page4 for reseal pressure information.
Back Pressure
High-Pressure Valves (ORV6A and ORV6B Series)
The effect of system back pressure is minimized by the design of these high-pressure valves.
ORV3 Series Back Pressure
Back pressure (backflow from outlet) may press the seat to form a seal in addition to the spring force in ORV3 Series Valves.
System back pressure increases the set pressure of the valve.
To compensate ORV3 Series valve properly, follow the steps below.
Step 1. Identify valve set pressure and system back pressure.
Step 2. Multiply back pressure by 0.8: 30 psig × 0.8 = 24 psig.
Step 3. Subtract it from the valve set perssure : 250 psig - 24 psig = 226 psig.
Step 4. Pre-set the relief valve to 226 psig
Materials of Construction
Flow Data
ORV6 Series
Spring Designator
ORV3 Series Spring Designator
ORV6 Series Spring Designator
Ordering Information and Dimensions
Set-Pressure Adjustment Procedure
- Select and install spring that covers the required set pressure.
- Turn lock nut on bonnet clockwise until it sits on the bottim thread of bonnet.
- Turn cap counterclockwise until spring fully relaxes.
- Pressurize the valve into inlet port.
- Check the pump pressure on gauge until it reaches required set-pressure while you turn cap clockwise to compress spring.
- Once the valve is preset to the required set-pressure, valve seat closes indication no flow in outlet port.
- De-pressurize the pressure thoroughly from the valve and turn lock nut counterclockwise until it locks out cap.
- Set the wire and apply matching label to cal.
Factory Test
Every valve that contains spring is factory-tested for set pressure and resealing performance.
For valves that do not contain spring, the seat is tested @ 1000 psig (69 bar) nitrogen for no detectable leakage.
How to Order
ORV3 Series is supplied containing "RVS0" spring that is not pre-set for cracking pressure unless "set-pressure at factory" is ordered.
ORV6 Series may be supplied with spring separately. To order, Select applicable valve basic ordering number, spring designator, seal and body material from the designators listed below.
Spring Kit
Contains spring, label, and lock wire with clamping seal.
ORV3 Series: ORV3-MK-RVS0
ORV6 Series: ORV6-MK-RVS1
