1.1 This Standard Practice provides dimensions, tolerances, and markings for butt-welding fittings for low pressure, corrosion resistant applications.
1.2 This Standard Practice covers only fittings made for use with Schedule 5S or 10S pipe, for all NPS sizes listed in ASME B36.19M, except that for short pattern stub ends suitable for use with Schedule 40S are also shown.
2.1 Standards and specifications adopted by reference in this Standard Practice are shown in Annex A for convenience of identifying edition number, date, and source of supply.
3.1 Fittings covered by this Standard Practice are not pressure rated; however, they must be capable of withstanding 30% of the allowable pressure rating of the pipe with which they are marked.
3.2 For fittings of same pressure rating of matching pipe, refer to ASME B16.9.
4.1 The size of the fittings in Tables 1 through 6 are identified by the corresponding nominal pipe size.
5.1 Each fitting shall be marked to show the following:
a)Manufacturer s name or trademark
b) CR followed by the material identification symbol established for the respective grade in the appropriate ASTM or AISI specifications
c) Manufacturer s heat identification number
d) Schedule number or nominal wall thickness designation
5.2 Where the size of the fittings does not permit complete marking, Sections 5.1 a) and c) are mandatory. The other marking and identification marks may be omitted in the sequence specified in MSS SP-25.
5.3 The required markings shall be made by any suitable method that is not injurious to the fitting.
6.1 Fittings made from AISI Types 304, 304L, 347, 316, and 316L are considered standard under this specification. Fittings made from other corrosion resistant material, including nonferrous, materials are acceptable by agreement between the purchaser and the manufacturer provided they meet the requirements of a recognized AISI or ASTM specification.
7. METAL THICKNESS
7.1 As these fittings are to match pipe, the dimensions of the welding ends must conform to established pipe standards as to outside diameters and tolerances. The nominal wall thickness of the fittings shall be the same as the pipe to which it is welded, except that fittings with heavier walls may be butt-welded to lighter wall pipe provided the heavier wall is tapered on the inside or outside to match the dimensions of the lighter pipe.
8. FITTINGS DIMENSIONS
8.1 Inch dimensions for the fittings covered by this Standard Practice are given in Tables 1 through 6.
8.2 One of the principals of this Standard Practice is the maintenance of a fixed position for welding ends with reference to center line of the fittings or the overall dimensions as the case may be.
9.1 Hydrostatic testing of fittings is not required in this Standard Practice; however, fittings shall be capable of withstanding a hydrostatic test pressure that is 1.5 times the pressure rating required in Section 3.1.
10.1 Table 1 lists the tolerances for the fittings covered by this Standard Practice.
11. WELDING BEVEL
11.1 Fittings furnished to this Standard Practice may be finished with ends cut square for wall thickness 0.12 in. or less. For wall thicknesses in excess of 0.12 in., they shall be beveled at 37 l/2 plus or minus 2 l/2 with root face (land) 0.06 in. plus or minus 0.03 in.
12. FINISH AND HEAT TREATMENT
12.1 The fittings shall be satisfactorily heat treated by an accepted practice, and adequately cleaned to insure maximum corrosion resistance. Pipe fittings list:
Butt Weld 45 Deg Lr Elbow | Butt Weld 90 Deg Lr Elbow | Butt Weld 180 Deg Lr Elbow | Butt Weld Concentric Reducer | Butt Weld Eccentric Reducer | Stub End | Butt Weld Equal Tee | Butt Weld Reducing Tee