Buckling Pin Valve
The most precise, accurate, and dependable valve for emergency shutdown isolation and flow diversion in petrochemical and industrial applications.
Product Overview
The Buckling Pin Valve is one of the most precise, accurate and dependable valves used in emergency shutdown for isolation and flow diversion. The valve features a clapper, disk, piston or plunger in an open position, restrained from movement by a slender, centerless ground pin that obeys Euler's Law.
When the pin is buckled, the valve is instantly closed. The pin is made of corrosion resistant alloys whose modulus of elasticity is constant over the ambient temperature range experienced by the valve.
Design Features
Proven buckling pin technology
Upstream pressure holds piston tightly on seat
Small buckling pin controls set point
Regulated opening rate
Positive shut off until pin buckles
Quick reseating, buckling pin may be changed in minutes
Minimal fugitive emissions
In overpressure event, there are no pieces to separate
No fragments flow to the downstream piping
Specifications
Constructed to ASME section VIII
Standard body materials include ASME SA234, SA105, and SA516-70; internals are ASME SA279-304 and 316 and SB149
Standard flange rating is ANSI 150# RF
Requirements for capacity are calculated using API 520 formulas
Quality documentation is available for all aspects of fabrication and testing
How It Works
Operation Principle
The Buckling Pin valve features a piston in an open position, restrained from movement by a slender, centerless ground pin that obeys Euler's Law. The pin is external to the system being protected and is held firmly on both ends.
The pin is engineered to buckle at an exact set point from an axial force applied by the system pressure acting on an unbalanced piston stem area. When the pin is buckled, the valve is instantly closed.
By using Euler's Law of Compressed Columns, the pins' diameter, length, and material can be determined and the set point accurately predicted, every time. The pin dimensions must be precise; we control the pin diameter by measuring to 5 decimal places and the length is measured to 4 decimal places.
Multiple Capabilities
Unlimited Size & Pressure Range
Buckling Pin valves have been successfully built from 1 inch to 18 inch diameter. Pressure set points from 5 PSI to 6,000 PSI. Vacuum can be set as low as 1 psi.
Flexible Pressure Sensing
Can be designed to sense system pressure or differential pressure based on your application requirements.
Corrosive & Dangerous Fluids
Handles corrosive and dangerous fluids with minimal operating expenses and no environmental concerns. System integrity is not compromised when resetting.
Special Materials Available
Can be made of special alloy materials, plastics, or glass lined to meet unique corrosive situations.
Proximity Sensor Option
Valves may be equipped with a proximity sensor to alert the operator of valve closing.
ASME Certified
Set point variation rarely exceeds +/-3% from set point; +/-1% is common
Quality Testing
All valves tested before leaving facility. Three pins tested on Tinius Olsen machine
Fast Shipping
Pin orders before noon on business days can be shipped the same day
Applications
Non-resetting pressure isolation valve applications
Emergency shutdown for isolation and flow diversion
Systems requiring operation closer to maximum operating pressures
Applications where premature failure prevention is critical
Environments requiring minimal environmental exposure during reset
Valve Maintenance
Checking Piston Movement
Remove the pin and apply pressure to the valve of no more than 10-20% of the set point. If the piston moves, the valve is in good shape.
To test under pressure, turn the pin holding nut one turn, no more. If the piston moves, the valve is reliable. Tighten the holding nut.
Note: The pin is never a concern. It obeys Euler's Law. If the piston does not move, remove the top assembly by loosening the bonnet bolts, remove the piston and replace the elastomer seals, reassemble and reset the Pin. Check to make sure the pin is not damaged or bent by rolling on a flat surface. The pin will have an infinite life if not damaged or bent.
Ready to Learn More?
Contact our technical team to discuss your specific application requirements and discover how Buckling Pin valves can benefit your operations.