The Food and Beverage sector faces a uniquely difficult range of challenges. From shifting consumer tastes to complicated regulations and interrupted supply chains, the industry is one of the fastest moving in the manufacturing world. As a result, production downtime is not an option when you have to constantly operate responsibly and efficiently whilst remaining competitive. For food and drink, the biggest cause of both downtime and operational loss is product spoilage.
One of the most important components in the food and drink manufacturing process is the Plate Heat Exchanger. There are four main types of plate heat exchanger: gasketed, brazed, welded and semi-welded. Gasketed plate heat exchangers (GPHEs) are the most common type of compact heat exchanger for food and drink processing. GPHEs are the unsung heroes of any food processing operation. They are compact and efficient devices designed for transferring heat between two fluids without allowing them to mix. The increased surface area of their distinctive plate design allows for improved heat transfer efficiency.
One of their primary purposes is to ensure precise temperature control during food processing, preserving the quality and safety of products. Additionally, GPHEs are instrumental in achieving energy efficiency, reducing production costs, and optimising productivity in food manufacturing plants. Central to the success of GPHEs, and by extension the whole operation, is the gasket. These vital components may be all but invisible in the production facility, but the materials they are made from need to be selected with great care, as gasket failure can lead to catastrophic operational loss.
Unintended Consequences
It is not without irony that progress in the food industry has brought with it some unintended consequences. In recent years, the shift towards natural food products has led to healthier lifestyles. However, many natural products have a lower heat tolerance than refined products such as sugar, and the consequences for GPHEs and their gasket seals are increased rates of particle fouling.
In turn, corrosion of the metal under the gasket seal can occur, and may be aggravated by chemicals released from the polymers used to make gaskets. Furthermore, polymer gaskets can also perish over time, whether that is due to UV light, incompatible fluids being heated to maximum temperatures for extended periods or excessive pressure. So selecting the right material cannot be overlooked.
Material Choice
NBR (Nitrile Butadiene Rubber)
NBR gaskets are renowned for their exceptional compatibility with both water and oil-based fluids. They are extensively utilised in plate heat exchangers across various industries, making them a reliable choice for ensuring leak-free seals. NBR is suitable for applications within a temperature range of -10°C to 110°C.
EPDM (Ethylene Propylene Diene Monomer)
Engineered to withstand the rigors of hot water, steam, and specific chemicals, EPDM gaskets stand out in high-temperature applications. They provide flexibility and resilience, making them a preferred choice in environments with elevated temperatures. EPDM gaskets are capable of maintaining their integrity even when exposed to temperatures ranging from -15°C to 150°C, ensuring reliable sealing in demanding conditions.
Viton
In settings characterised by extreme temperatures and corrosive substances, Viton gaskets shine. They exhibit remarkable resistance to harsh elements, providing longevity and reliability even in the harshest conditions. Viton gaskets are specifically designed to handle temperatures ranging from -10°C to 160°C, making them an ideal choice for applications where temperature fluctuations are prevalent.
Beyond a material’s ability to tolerate different operational environments and resistances, the effectiveness of a gasket in maintaining a reliable seal is heavily influenced by its thickness and hardness. Understanding the interplay between these two factors is essential for preventing leakage and ensuring the longevity of the gasket.
Thickness: Matching Pressure Requirements
In high-pressure applications, thicker gaskets are often employed. These gaskets provide enhanced resistance against the forces exerted, ensuring a secure seal. However, it’s crucial to strike a balance — excessively thick gaskets can lead to uneven distribution of pressure, potentially causing leaks.
Hardness: Conformability for a Secure Seal
Softer gaskets exhibit greater conformability, allowing them to adapt to irregularities in the sealing surfaces. This characteristic is particularly advantageous when dealing with surfaces that may not be perfectly flat. However, it’s important to note that softer gaskets may be more susceptible to wear and compression over time.
Ask The Experts
From picking the perfect gasket material to understanding the subtleties of thickness and hardness, choosing the right material for GPHE gaskets is key to optimising performance and ensuring minimal downtime and wastage. With over 60 years in the business, our technicians at Dobson Gaskets are available to discuss individual application requirements, and work with our clients to produce the right gasket for the job. To discuss your gasket needs, get in touch with us today.