Knowledge base
The plates and the gaskets are the two materials that decide how long a plate heat exchanger lives. The right choice depends less on the price than on what flows through the unit: the chemistry of the water, the glycol, the temperature and the cleaning. This guide explains the common materials and the questions that point to each.
Plate Materials
Stainless steel is the common choice for clean water and glycol circuits: strong, hygienic and widely available. Where the water carries chlorides - sea water, brackish water, some well water - ordinary stainless can suffer pitting and cracking, and titanium or a higher alloy is chosen instead. Nickel alloys and other special materials serve aggressive chemicals and demanding conditions. Brazed units use stainless plates joined with copper or with another filler, which also has to suit the fluid.
Gasket Materials
In a gasketed unit the gaskets are elastomers, and each kind tolerates a range of temperatures and fluids. Some resist hot water and glycol, others oils and fuels, others aggressive chemicals; the wrong one swells, hardens or leaks. The gasket is also the part that wears, so it is chosen for the temperature, the fluid and the cleaning chemicals it will meet, and the supplier of the exchanger states which one is fitted.
What Decides The Choice
The fluids on both sides come first, with their chemistry, glycol mixture and any additives. Chlorides in the water are the single most common reason to move from stainless to titanium. Temperature affects both the plate and the gasket. The expected cleaning method matters, because some cleaning liquids attack some materials. And the life expected and the cost of a failure tell how far to go: a plant that cannot stop is better served by a more resistant material than the cheapest one.
Say It In The Enquiry
The simplest way to get the right material is to describe the fluids honestly, including the water analysis where there is one. TECS Engineering designs and delivers plate heat exchanger solutions for engine, power plant and industrial cooling circuits; send the fluids, the temperatures and the conditions of the site, and the engineering team will answer.
In Short
- Stainless steel for clean water and glycol circuits
- Titanium or higher alloys where chlorides are present
- Special alloys for aggressive chemicals
- Gasket elastomers matched to the fluid, the temperature and the cleaning
- Fluids, chlorides, temperature, cleaning and life decide
- A water analysis in the enquiry avoids a wrong material
What To Send With An Enquiry
- The fluids on both sides, glycol mixture, additives
- Water analysis, including chlorides, where available
- Temperatures on both sides
- How the unit will be cleaned and with what
- Expected life and the cost of a stoppage
- Any owner or classification material specification
Questions We Are Often Asked
What are plate heat exchanger plates made of?
Most often stainless steel. Titanium and nickel alloys are used for sea water, chlorides and aggressive fluids.
Why is titanium used for sea water?
Ordinary stainless steel can pit and crack in chloride-rich water, and titanium resists it.
Are gaskets all the same?
No. Each elastomer tolerates certain fluids and temperatures, and the wrong one swells, hardens or leaks.
What should I tell the supplier about the water?
Its source and, where there is one, its analysis, especially the chlorides and the hardness.
Does the cleaning method affect the material?
Yes. Some cleaning liquids attack some plate or gasket materials, so the cleaning plan is part of the choice.
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.
