Two types of Pressure Relief Valves • Resetting • Non Resetting Three types of Non-resettingPressure Relief Methods • Rupture / Buckling Pin • Rupture Disc • Shear / Breaking Pin
Shear / Breaking Pin Valves Shear pin valves are designed to shear a pin, in the horizontal position, that sits on a piston with sharp edges. When the pressure reaches set pressure, the pin is sheared. • Pulsation will damage shear pin. • Time will dull piston edges designed for shearing. • Can only sense system pressure. Not reliable or accurate. NOT ASME APPROVED!
Rupture disk is an internal device. You will need some sort of an indicator to show a leaking or burst disk. Rupture Disk Rupture disk will require extended downtime to break the integrity of your system to inspect or change. Rupture disk must be installed properly by experienced personnel and may require protective equipment.
Rupture disk have a manufacturing allowance and an ASME tolerance. The Rupture Pin Valve only utilizes the ASME tolerance of + 5%. There is no manufacturing allowance. THE RUPTURE PIN VALVE OPERATES AT +95% OF SET PRESSURE.
Mr. Taylor invents the Rupture Pin Valve using Euler's Law of Compressed Columns • 1987-90 obtains patent and ASME acceptance for the Buckling Pin Technology. • Commercial sales starts in 1990 through Rupture Pin Technology. Buckling Pin Accepted • ASME Section VIII Division I Code Case 2091-3 • API RP-520 Part One – Section 2.4 • The National Board of Boiler and Pressure Vessel Inspectors – (Test system is protected by a Rupture Pin Technology valve.)
Rupture Pin Valve protecting the system at The National Board Testing Laboratory in Columbus, OH
Introduction • Proven technology based on Physical Law – Euler’s Law of Compressed Columns – (like the Law of Gravity) • Allows you to solve difficult problems with pressure relief and emergency shutdown • The technology relies on a simple, precise pin that senses an axial force and obeys Euler’s Law. • The pin acts as a trigger to open or close a bubble tight valve (ASME class 6) element in milliseconds.
Euler’s Law of Compressed Columns PIN DIAMETER4 x PIN MATERIAL MODULUS OF ELASTICITY AXIAL FORCE ON THE PIN CAUSING THE PIN TO BUCKLE ~ PIN LENGTH2 (piston/plunger surface area x system pressure)
The Pin • A slender, round column, precise in its diameter, length, and metallurgy that obeys Euler’s Law. • The pin ends are restrained for precise, repeatable operation • Pin has only two stable conditions: Straight or Buckled • The buckling point is accurately repeatable with no adverse buckling point variation. • The pin cannot fail early due to fatigue or pulsation.
The Pin Characteristics • Obeys Euler’s Law precisely • The buckling point is exact, ± 5% of set point is standard, ± 2% of set point is common with actual valve test certificates • The pin is external from aggressive system fluid • No Temperature correction is required • Bows elastically to allow a slight axial piston movement before buckling • Currently have built valves from 1/8” to 36”
Tinius-Olsen Test • Increase of force on pin • A rapid fall-off of pin resistance • Speed of buckling • The opening of the valve is about 10 times faster than a rupture disk. 1.7 milli-seconds
This graph will show how the rupture disk will exceed the elastic limit (1) of the material and not burst (3); therefore changing the basic properties of the material and burst pressure. The buckling pin will buckle when it gets to the elastic limit (1) of the pin material; therefore fatigue and pulsation are not a factor.
The Rupture Pin AdvantageOver Conventional Relief Systems • Conventional spring loaded relief and pilot valves leak close to set pressure, and have problems reseating tightly. • Designed to begin relieving at 90% of set pressure and require 10% over set pressure for full capacity. • Spring loaded must be recertified at least once a year. (Depending on State Laws and Company Policies.) • Poor accuracy below 15 psi, and limited reliability over 3,000 psi. Rupture Pin valves are accurate through all pressure ranges.
Rupture Pin Valvemounted before aTaylor Pressure Safety Valve • Protects PSV from pulsation and fatigue • No orifice restriction before PSV • Full bore flow thru Rupture Pin Valve • Bubble tight seal until set point • Balanced piston design so “trapped” pressure between valves is not a factor • No line breakage and easily reset to get back into operation • No recertification required for the Rupture Pin Valve • Extends the life of the PSV • No tattletale required • No trash after relief to damage PSV
Valve BasicsModel “C” Relief Valve Rupture Pin resists the force of the system pressure acting on the piston area. Pin buckles at a precise set pressure in milliseconds according to Euler's Law of Compressed Columns. Piston is only moving part. Piston on which system pressure acts. Notice o-ring seal is on vertical surface inside of Seat. Bubble tight seal until pin buckles. Full bore relief instantaneously. CLOSED - PRESSURE BELOW SET POINT FULL OPEN - PRESSURE AT SET POINT
Valve BasicsModel “C” Relief ValveWith Balanced Piston Equal Surface Areas Creating equal opposing forces negating downstream pressures. The balanced piston has equal surface areas creating opposing forces; therefore negating any downstream pressure. Valve will sense system pressure only.
16” Model C Mr. Lee Sudik our “Pin Guru”
Mr. Taylor with 36” Model C This valve was built for ARAMCO, the Saudi Arabian oil company. Notice the two stable conditions of the buckling pin – straight or buckled. The pin Mr. Taylor is holding, is 1 1/8” in diameter and 48” long. The set pressure of this valve is 36 psig. This illustration shows that you can’t tell set pressure by pin size. Pin size is determined by Euler’s Law.
These past photos show our ability to custom build valves to solve your problems. 1/2” Solid Titanium
The valve may be orientated in any direction. We just need to know how the customer is going to mount the valve so we can consider it when setting the pin. If we are not told any different we will set the pin with the valve mounted vertical. Huntsman Corporation – Texas City, TX
Model “D” Inline Relief Valve Closed Open The Model D valve is used when you need to install a valve in a straight line.
notice proximity switch Will give an immediate signal when a valve is activated.
Easy pin storage at the valve. notice pin holder
Model CMSteam Jacketed ValveWith Flush Port The piston face is flush with the process piping, steam jacketed piping for heating, and flush port for cleaning the seat before reseating the piston.
Piston will be flush with inside of vessel. Georgia-Pacific Paper Company Dial Soap Corporation
To: Lee Levisay From: Don Berry, Georgia-Pacific, Wauna Re: Rupture Pin Date: November 3, 2004 Lee, I would like to thank you for introducing me to your product. Previously we were using a rupture disc from XXXX Inc. While this was a good product, the time to change the disc is 10x as much as the time to change the buckling pin. In addition to the ease of maintenance, I am impressed with the amount of (or lack of) preventative maintenance on your Pressure relief devise. Again, your buckling pin has saved us money already and will continue to do so in the future. In the future, if any of your customers would like to talk to me before they make their decisions, please have them give me a call. Don Berry Georgia-Pacific, Wauna Bleach Plant Maintenance Planner/ Supervisor
15,000 psi set pressure 4 at 9500 psi set pressure Shell Offshore – Auger Platform – Gulf of Mexico
This is a good example where the Rupture Pin Valve replaced conventional spring loaded valves. The valves are mounted on the discharge of positive displacement chemical injection pumps. The conventional valves were fatiguing and leaking due to the pulsation factor. Shell Offshore found that our valve would keep a bubble tight seal until the system was over pressured. They would then get a signal from the proximity switch or visual indicator by observing the pin condition.
Model IHigh Pressure - High Volume Valve Notice the pressure is sensed on the stem area and not on the piston face. The lower o-ring sealing area is smaller then the upper o-ring sealing area; therefore creating an axial force that is much lower and easier to control.
ExxonMobil Chemical – Baton Rouge, LA 2” valve with a 5500 psi set pressure This valve is installed downstream of a compressor because the pulsation will not fatigue the pin or change the set pressure.
Options to Rupture Pin Valves Fire Safe Holding Nut Proximity Switch On Site Pin Holder Pin Guard
Typical Customers • Chemical – Agrium, Arizona Chemical, Eastman Chemical, GE Plastics, National Starch • Food Processing – Amalgamated Sugar, Miller Brewing Co., Carnation • Pharmacial – Bayer, Baxter Medical, Eli Lilly • Pipeline – Alyeska Pipeline Service Co., TEPPCO, Olympic Pipeline, ConocoPhillips Pipeline, El Paso Natural Gas, Enterprise Prod. • Production – Phillips Alaska, Shell Offshore, BP Exploration, ExxonMobil, Unocal Oil & Gas • Pulp & Paper – Georgia Pacific, International Paper, Stone Container, Weyerhaeuser