General options
The materials determine how long a strainer lasts in the medium. We manufacture housings in carbon steel and stainless steel, strainer elements in stainless steel throughout – and for aggressive media in duplex, Monel or Hastelloy. Housing and element can be selected independently of each other.
P235GH · P250GH
1.4571
1.4301 · 1.4401 · 1.4404
Duplex · Monel · Hastelloy
A strainer is permanently in contact with the medium. What the pipeline can withstand, the strainer cannot necessarily withstand: in the housing the medium is stagnant, in the strainer element it flows through narrow openings. Both promote corrosion at points where it does not occur in a straight pipe run.
That is why we select the housing and element separately. A carbon steel housing with a stainless steel screen is the rule – the housing carries the pressure, the screen sits in the flow. With chlorides, acids or seawater this is not enough; duplex or nickel-based alloys are used there.
We clarify which material is suitable before quoting – based on medium, concentration, temperature and operating pressure. On request with inspection certificate 3.1 to DIN EN 10204.
It concerns the housing. The strainer element is always made of stainless steel, regardless.
The standard for housings and flanges with neutral media such as cooling water, heating water or mineral oil. Primed and painted, RAL 5010 blue as standard. Suitable up to the highest pressure rating and economical to manufacture.
As soon as moisture combined with oxygen, chlorides, acids or cleaning agents come into play. Pickled and passivated, giving a closed passive layer. 1.4571 is titanium-stabilised and resistant to intergranular corrosion after welding.
The material number matters more than the trade name. That is why we state it throughout – in the quotation, on the nameplate and in the inspection certificate.
| Material | Designation | Application |
|---|---|---|
| Carbon steel housings and flanges | ||
| Carbon steel P235GH | 1.0345 | Housings for neutral media, primed and painted in RAL 5010 |
| Carbon steel P250GH | 1.0460 | Flanges and housings, same application as P235GH |
| Stainless steel housings and flanges | ||
| Stainless steel 1.4571 | X6CrNiMoTi17-12-2 | The standard. Titanium-stabilised, pickled and passivated |
| Stainless steel 1.4404 | X2CrNiMo17-12-2 | Pot type strainer housings. Very low carbon content, easy to form and polish |
| Strainer element | ||
| Stainless steel 1.4401 | X5CrNiMo17-12-2 | Fine mesh screen and wire mesh |
| Stainless steel 1.4301 | X5CrNi18-10 | Support basket, screen ring and screen plate |
| Special alloys | ||
| Duplex | ferritic-austenitic | Seawater and chloride-containing media. Higher strength, considerably more resistant to stress corrosion cracking |
| Monel | nickel-copper | Hydrofluoric acid, seawater at elevated temperature, reducing conditions |
| Hastelloy | nickel-molybdenum-chromium | Hot hydrochloric acid, sulphuric acid, strongly oxidising and reducing media |
| Castings for Y strainers | ||
| Cast steel and grey cast iron | ductile iron · gunmetal | Housings of Y strainers, depending on pressure rating and medium |
Other materials on request. We make the selection together with you based on medium, concentration, temperature and operating pressure.
Standard design. Deviations are possible for each component individually.
Chlorides are the most common reason. They attack austenitic stainless steel as soon as temperature and concentration coincide – typically in seawater, cooling circuits with additives and in the chemical industry. Duplex withstands considerably more here. For hydrofluoric acid, hot hydrochloric acid or strongly reducing conditions, the way leads to nickel-based alloys. Tell us the medium, concentration and temperature – we propose the material and explain our choice.
For neutral media such as cooling water, heating water or mineral oil, a carbon steel housing, primed and painted, is sufficient. As soon as moisture combined with oxygen, chlorides, acids or cleaning agents are involved, stainless steel is the right choice. The strainer element is always made of stainless steel anyway.
Both are molybdenum-alloyed stainless steels with similar resistance. 1.4571 is stabilised with titanium and therefore less susceptible to intergranular corrosion after welding. 1.4404 has a very low carbon content and achieves this in a different way – it is easier to form and polish.
Yes, that is actually the rule. A carbon steel housing with a support basket in 1.4301 and a fine mesh screen in 1.4401 is the most common combination. The housing carries the pressure, the element sits in the flow – the requirements are different.
Yes. Inspection certificate 3.1 to DIN EN 10204, bilingual on request. Design is to AD 2000, manufacture to the Pressure Equipment Directive 2014/68/EU.
Austenitic stainless steel reaches its limit with chlorides. For seawater and chloride-containing circuits we use duplex, and nickel-based alloys for higher exposure. The selection depends on temperature, chloride content and flow.
All topics at a glance: Strainer options
Tell us the medium, concentration, temperature and operating pressure – we propose the material for the housing and strainer element.
