Piping Materials : Strainers

Clause Details
STR-MAT-001 There are three types of strainers : Temporary Strainer, Y strainer and T Strainer.
STR-MAT-002 Temporary strainer is a startup strainer, also known as conical strainer, and is installed in a system to remove unwanted debris from the proces stream.
STR-MAT-003 Temporary strainer is installed to protect a flow meter, pump, control or relief valves or other pieces of equipment during startup.
STR-MAT-004 During construction, materials may become trapped in the line. These materials could be welding slag, welding rod, pieces of wood, cigarettes, rocks, etc. Many pieces of equipment will become damaged if this debris enters it.
STR-MAT-005 After start up is completed, the startup strainer should be removed.
STR-MAT-006 Materials of construction of a strainer should be compatible with the fluid.
STR-MAT-007 If a strainer cannot withstand high temperatures or differential pressures, it could come apart and cause damage to equipment.
STR-MAT-008 The expected pressure drop across the strainer should not cause the downstream operating pressure to fall below the minimum required pressure of the line e.g. NPSH for a pump.
STR-MAT-009 The perforations of the strainer should be slightly smaller than the smallest piece of debris that is expected to flow through it. If the perforations are too small, a high pressure drop could develop across the strainer and cause it to fail.
STR-MAT-010 Strainer should be easily removed by adding a pipe support or pipe stand close to the strainer and/ or a removable spool so that the strainer can be removed easily.
STR-MAT-011 It should be possbile to remove the temporary strainer without shutting down the process with the help of a redundant piece of equipment that can be used while the strainer is being removed, or with block valves to allow bypass the strainer.
STR-MAT-012 Do not install a strainer immediately upstream of a piece of equipment that is sensitive to the flow regime, such as an orifice plate. If possible, install the strainer downstream.
STR-MAT-013 At the flange, the temporary strainer is usually 1/16” and it also requires two gaskets. When the strainer is removed, it must be decided how will the pipe be connected again without double or triple stacking gaskets.
STR-MAT-014 A temporary strainer can add 1/8” to the length of the bolts. Some companies require full thread engagement when installing piping and the extra 1/8” can be added to the bolt size.
STR-MAT-015 Installation of a conical strainer can be done in one of two different ways, cone facing upstream or cone facing downstream.
STR-MAT-016 When cone is downstream, debris collects inside of the cone near thetip and cone may rip apart due to heavy strain on the tip.
STR-MAT-017 Advantage of cone downstream side is easier removal of debris. But mechanical strength of cone shall be ensured.
STR-MAT-018 When cone is upstream, debris collects to the side of the strainer. Its advantage is that any plugging of the strainer will start in the outside and work its way in.
STR-MAT-019 The y strainer is normally used in small bore lines and where there is a small amount of material to be collected.
STR-MAT-020 Y-strainer can be installed in horizontal or vertical position.
STR-MAT-021 T-Strainer is used in big bore lines 2″ and above.
STR-MAT-022 MOC for T-Strainer is Wrought steel buttwelding material : ASTM A234 Gr. WPB for carbon steel and ASTM A403 Gr. WP304L-S for stainless steel.
STR-MAT-023 Screen for all strainers are made from stainless steel 304SS, 306SS.
STR-MAT-024 Y-Strainers are threaded or socket welded.
STR-MAT-025 MOC for Y-strainer is Forged Material ASTM A105 for carbon steel, ASTM A182 Gr. F304L.
STR-MAT-026 Bronze Y-Strainers are as per ASTM B62.
STR-MAT-027 Dimensional Standards are manufacturer specific.

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