Fittings Specifications

This Standard for threaded malleable iron fittings Classes 150, and 300 provides requirements for the following:

  • (a) pressure-temperature ratings
  • (b) size and method of designation openings of reducing fittings
  • (c) marking
  • (d) materials
  • (e) dimensions and tolerances
  • (f) threading
  • (g) coatings

Pressure-temperature ratings can be found in the table below:

Pressure-Temperature ratings for malleable iron threaded fittings (psig)
TemperatureClass
150300
(°F)(°C)1/4 - 1 inches1 1/4 - 2 inches2 1/2 - 3 inches
-20 to 150 -29 to 66 300 2000 1500 1000
200 93 265 1785 1350 910
250 121 185 1575 1200 825
300 149 150 1360 1050 735
350 177 - 1150 900 650
400 204 - 935 750 560
450 232 - 725 600 475
500 260 - 510 450 385
550 288 - 300 300 300

*1 psi = 0.0689 bar = 6.89 kPa
** Every effort has been made to insure the accuracy of this chart, for critical applications consult a qualified engineer.

Elbows

Stub Ends

Tees

Crosses

Caps

Reducers

Contact Us

(713) 733-5500
Fax: (713) 733-5676