Trelleborg Sealing Solutions develops materials for Plate Heat Exchanger gaskets
Trelleborg Sealing Solutions is one of the leading suppliers of gaskets fitted to Plate Heat Exchanger systems and develops materials specifically for their challenging requirements. Three materials have been developed recently to meet the needs of particular applications.
Plate Heat Exchangers (PHEs) are an integral part of many processing plants, ensuring efficient energy use for heating and cooling, minimizing overall heat loss and helping protect the environment. The plates within PHEs are sealed with a rubber gasket that prevents the liquids within the PHE leaking out or mixing.
Image shows PHE plate and gasket
Leading supplier of PHE gaskets
“Gaskets are critical elements within a PHE and potentially their weakest link,” says Jon Cutler, Trelleborg Sealing Solutions Material Development Manager for PHE gaskets. “We’ve been making them for more than 25 years and customers rely on our material expertise. We’re taking gasket compounds to the limits of their performance. Great efforts have been made to ensure gasket material longevity at high temperatures and pressures.”
Sealing in PHEs is challenging. Temperatures are at extremes from –49°F to +392°F/–45°C to +200°C, while chemicals can be exceptionally aggressive. Pressures are also reasonably high, generally between 72 and 218 psi / five and 15 bar, but sometimes even up to 508 psi/ 35 bar.
Image shows typical Plate Heat Exchangers
Three new materials to meet demanding PHE requirements
Materials have been specifically developed to meet the needs of particular applications. Below are details of three recent developments.
Material designation: 09-538/E8ZP4
The material of choice for around 30 percent of all PHE gaskets produced is EPDM. Careful compounding of this material type to ensure optimum heat resistance and improved aging has resulted in an EPDM that is capable of operating for a minimum of one year at +347°F/ +175°C in a hot water or steam environment.
Material designation: 09-560/E9291
A hard EPDM material with enhanced chemical resistance was offered to a customer who had experienced poor performance from a competitor’s gaskets when processing methyl t-butyl ether (MTBE). This gave excellent results and gaskets of this compound are now fitted in the customer’s PHEs where this medium is in the process stream. The material is ideal for contact with formaldehyde, organic acids and the amines used for gas sweetening. It is also suitable for chlorate production.
Material designation: 26-006/H8ZP1
A customer operating in offshore oil and gas exploration required a HNBR with superior high-temperature capabilities for use in oil coolers. Maximum hydrolysis resistance of the gasket material was required as hot water and steam (used in most plate heat exchangers) are potentially more damaging to HNBR than hydrocarbon products. After working on developing such a material for over 10 years, Trelleborg Sealing Solutions now offers a grade with proven continuous operating temperatures up to +347°F/ +175°C.
Diagram of a typical Plate Heat Exchanger
Plate Heat Exchangers
The design concept for all PHEs is the same. Between two metal end plates there is a series of thin metal plates close to each other. The liquid to be processed is pumped into one side of the plates while the liquid facilitating heating and cooling is pumped into the other. The key to the process is that both liquids come into contact with the maximum plate surface area to rapidly exchange heat from one liquid to the other.
In processing plants PHEs can be up to 16 feet/ five meters in height. The largest length is 13 feet/ four meters and plate width is five feet / one and a half meters, which is the maximum size that strip steel can be produced. Plates will range from this size down to about 11 inches/ 280 millimeters long and four inches/ 100 millimeters wide. The PHE gaskets have to match the size of the plates with thicknesses from 0.08 inches/ two millimeters up to 0.8 inches/ 20 millimeters.
For more information on Plate Heat Exchanger gaskets contact your local Trelleborg Sealing Solutions marketing company.