Design Code

  • Y – Type : ASME B31.3
  • T – Type : ASME B31.3
  • C – Type : ASME B31.3
  • B – Type : ASME SEC. VIII DIV.1


Strainers are installed on gas or liquid pipes to protect equipments from foreign matters such as rust, scale, weld slag and sand.

It is usually installed on pumps, flow meters, various control valves, steam traps, spray nozzles and turbines.

It can also be installed on heat exchangers if necessary.


The structure is simple. It has a body, Element (perforated plate and wire mesh) which filters out foreign matter, and a cover or cap for pulling and pushing the screen.

The Element generally uses Perforated Type and Mesh Element, which is a fixed wire mesh and a perforated plate,

The hole size of Wire mesh is depend on foreign matter’s size and protector, it is usually 10, 20, 30, 40, 60, 100, 200 mesh. The hole size of perforated plate is usually used 3mm, 4mm, 6mm, 8mm, 10mm.

Sizes 20~60 are generally used for liquids, air or gas applications generally utilize more than 80 or higher.

Be careful if you use more than 200 size of mesh because of a large pressure loss.

An accumulation of foreign matter in the element can cause a loss of pressure and low level of flow. Make sure there is enough effective area and filter area in the strainer.

It depends on the fluid type and caliber but the filter area, which is area of Element when it is spread, has to 5 – 7 times bigger than plumbing cross-section area.

The effective area, the way that fluid goes though, should be at least more than 2 – 3 times bigger than plumbing cross-section area.


A blow-down valve can be set up in the cap of the strainer in order to easily clean foreign matter off of the Element.

Take caution when setting the strainer up in front of a cooling-tower pump. Much foreign matter can collect causing fluids to run low and cavitations may form.


Material of Strainer

• Carbon Steel ASTM : A105, A216WCB , A53, A234, A106 , A516
• KS : SCPH2, SPPS, SPHT, SB42, S25C
• Stainless Steel : A182, A351, A312, A403, A240
• Alloy Steel and Special Steel : Monel, Hastelloy, Aluminium, Bronze, Copper Alloy, Chrome Steel, etc.

End Connection Style of Strainer

• Flange Type (SO/RF/RTJ)
• Socket Weld Type (SW)
• Butt Weld Type (BW)
• Screw Type ( PT & NPT )

Application Code

• KS & JIS & DIN

Internal Element of Strainer

Element is very important part as the heart of strainer.

So, Corrosion Resistance, Filtration rate and Strength must be considered sufficiently and it

must be a structure not to be bypassed the non-filtered fluid between element and body.

FILSON’s is manufacturing a high credible strainer that can’t compare with other products

as it has a long experience and accumulated know-how in field of engineering.

Perforate Plate

Mesh Table

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