Knowledge base
A plate heat exchanger is not one product but three families, and the difference lies in how the plates are sealed to each other: with gaskets, by brazing or by welding. The choice decides whether the exchanger can be opened and cleaned, what fluids and temperatures it can carry and how long it will last. This guide compares the three in plain terms so the right kind can be picked before the details are worked out.
Gasketed Plate Heat Exchangers
In the gasketed type the plates are hung on a frame and pressed together with bolts, with a rubber-like gasket sealing each channel. The great advantage is access: the pack can be opened, the plates cleaned and the gaskets replaced, and plates can be added or removed when the duty changes. That makes it the usual choice for heating and cooling circuits with water or glycol where regular cleaning is expected. Its limits are set by the gasket material, which restricts the fluids and the temperature and pressure it can take, and by the gaskets themselves, which are a wear part.
Brazed Plate Heat Exchangers
In the brazed type the plates are joined permanently in a furnace and the unit is a sealed block without a frame or gaskets. It is the most compact and the least expensive way to get a plate exchanger, and it is common in engine circuits, refrigeration, heat pumps and building services. The price of that simplicity is that it cannot be opened: when it fouls it can only be flushed with chemicals, and when it fails it is replaced. It suits clean, closed circuits with fluids that are well treated.
Welded Plate Heat Exchangers
In welded designs the plates are welded together, wholly or in pairs, so that no gasket is needed on the side that carries the demanding fluid. This lets the exchanger work with aggressive fluids, higher temperatures and higher pressures than a gasketed one, while some designs keep a part of the pack accessible for cleaning. It is a heavier and more costly construction and is chosen when the fluid or the conditions rule the other two out.
How To Choose
Three questions decide it. How clean is the circuit, and will it need to be opened? A closed, treated circuit allows a brazed unit; a circuit that fouls calls for gaskets or a design that can be cleaned. What are the fluids, temperatures and pressures? Aggressive fluids and harsh conditions point to welded construction. And will the duty change? If it may grow, a gasketed unit that can be extended is the safer choice.
TECS Engineering designs and delivers plate heat exchanger solutions for engine, power plant and industrial cooling circuits. Send the fluids, the flows and temperatures and the conditions of the site, and the engineering team will answer with the right kind of exchanger.
In Short
- Gasketed: opened, cleaned and extended; limited by the gasket material
- Brazed: sealed, very compact and economical; cannot be opened
- Welded: for aggressive fluids and demanding conditions; heavier and dearer
- Closed, clean, treated circuit: brazed is common
- Circuit that fouls or may grow: gasketed
- Aggressive fluid or harsh conditions: welded
What To Send With An Enquiry
- The fluids and their cleanliness; glycol mixture if any
- Heat duty, flows and temperatures
- Pressure and temperature of each side
- Whether the unit has to be cleaned or extended later
- Space available and the connection arrangement
- Site conditions and any material specification
Questions We Are Often Asked
What are the main types of plate heat exchanger?
Gasketed, brazed and welded. They differ in how the plates are sealed to each other, which decides whether they can be opened, and the fluids and conditions they can carry.
Which type can be cleaned?
The gasketed type can be opened and the plates cleaned or replaced. A brazed unit can only be flushed, and a welded one only partly, depending on the design.
Why is the brazed type so common in engine circuits?
It is compact, economical and has no gaskets to leak, and an engine circuit is closed and treated, which suits a sealed unit.
When is a welded plate exchanger needed?
When the fluid is aggressive or the temperature or pressure rules out gaskets.
Can a plate exchanger be extended later?
A gasketed unit can usually have plates added within the limits of its frame. A brazed unit is a sealed block and cannot.
Contact Us
Send us the heat duty, the fluid temperatures and flow rates, the ambient conditions and the installation limits. We answer with a design proposal - or write to us on WhatsApp.
