Piping Materials : Buttweld Fittings

Clause Details
BWF-MAT-001 Buttweld Fittings are normally used for pipe sizes 2″ and above.
BWF-MAT-002 ASME B16.9 is the dimensional standard for Buttweld Fittings.
BWF-MAT-003 In B16.9, Long Radius Elbows, 3D Bends, Straight Tees and Crosses, Reducing Tees and Crosses, Caps and Reducers are available upto 48″
BWF-MAT-004 In B16.9, Short radius elbows, Long Radius Returns, Short Radius Returns, Lap joint stub ends are available upto 24″
BWF-MAT-005 They are Factory Made Wrought Steel Fittings. (Worked).
BWF-MAT-006 Buttwelding fittings have smooth inner surface and offer gradual direction change with minimum turbulence.
BWF-MAT-007 They require much less space for constructing and hanging the pipe system.
BWF-MAT-008 They are maintenance free, reliable and leak proof.
BWF-MAT-009 They have higher temperature and pressure limits.
BWF-MAT-010 These fittings are easy to insulate.
BWF-MAT-011 They offer uniform wall thickness throught the system.
BWF-MAT-012 These fittings are not easy to dismantle compared to threaded or other non-welding joints.
BWF-MAT-013 Enough flanges should be provided in system to easily dismantle the system.
BWF-MAT-014 There is possibility of intruding weld metal at the joint which could affect the flow.
BWF-MAT-015 Long radius elbows with elbow radius of 1.5D are preferred due to low pressure drop.
BWF-MAT-016 Short radius elbows with elbow radius of 1xD are used where space constraint exist.
BWF-MAT-017 180 degree returns are used to construct heating coils, vents on tanks etc.
BWF-MAT-018 Bends are made from straight pipe. Common bending radii are 3 and 5 times the pipe size (3R and 5R bends, where R=Nominal Pipe Size – nominal diameter – not radius).
BWF-MAT-019 3R Bends are available from Stock.
BWF-MAT-020 Larger bends can be custom made, preferrably by hot bending.
BWF-MAT-021 Only seamless or electric-resistance-welded pipe is suitable for bending.
BWF-MAT-022 Flat closures are normally cut from the plate stock by the fabricator or the erector.
BWF-MAT-023 Stub in is a term for a branch pipe welded directly into the side of the main pipe run – it is not a fitting. This is the commonest and least expensive method of welding a full-size or reducing branch for pipe 2-inch and larger. A stub-in can be reinforced.
BWF-MAT-024 For economy, availability and to minimize the number of items in inventory, it is preferred to use tees etc. and not crosses except where space is restricted, as in marine piping or revamp work.
BWF-MAT-025 Reducing laterals are ordered similarly to butt-welding tees, except that the angle between branch and run is also stated.
BWF-MAT-026 Thickness of the buttwelding fitting to be specified same as matching pipe to be welded to it.
BWF-MAT-027 Heat treatment is necessary for Buttwelding Fittings.
BWF-MAT-028 Cryogenic Temperatures Stainless Steel : -100 deg. C to -250 deg. C : A403 Gr. 304, 304L, 316, 316L etc.
BWF-MAT-029 Low Temperature Carbon Steel : -30 deg. C to -100 deg. C : ASTM A420 WPL6
BWF-MAT-030 Intermediate Tempeatures Carbon Steel : -30 deg. C to 430 deg. C : Material used is ASTM A234 Gr. WPB for Seamless and Gr. WPBW for Welded Fittings.
BWF-MAT-031 High Temperature Alloy Steel : 430 deg. C to 630 deg. C : Material used is A234 Gr. WP1, WP11, WP12, WP22
BWF-MAT-032 Elevated Temperatures Stainless Steel : 630 deg. C to 815 deg. C : Materia Used is : A403 WP304H, 316H, 327H, 312.

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