API 623 Trim Chart

API 623 trim material chart for all trim number, such as trim 1, 2, 3, 4, 5, 5A, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 etc.

Table 8—Nominal Seating Surface, Stem, and Backseat Bushing or Weld Deposited Materials and Hardness

Table 8 —Nominal Seating Surface, Stem, and Backseat Bushing or Weld Deposited Materials and Hardness (Continued)  

Table 8—Nominal Seating Surface,Stem,and Backseat Bushing or Weld Deposited Materials and Hardness (Continued)

Table 8 —Nominal Seating Surface,Stem,and Backseat Bushing or Weld Deposited Materials and Hardness (Continued)  

NOTE Cr = chromium; Ni = nickel; Co = cobalt; Cu = copper; NA = not applicable.

^a HB (formerly BHN) is the symbol for the Brinell hardness per ASTM E10.

^b Free machining grades of 13Cr are prohibited.

^c Typical backseat weld deposit material.

^d Manufacturer’s standard hardness.

^e Diferential hardness between the body and disc seat surfaces is not required.

^f Case hardness by nitriding to a thickness of 0.13 mm (0.005 in.) minimum.

^g AWS 5.13 ECoCr-A or AWS 5.21 ERCoCr-A. This classifcation includes trademark materials. For plasma transfer arc welding (PTAW), process powder with the metallurgy equivalent to UNS R30006 can also be used. CoCr-E may be used only with purchaser approval, and typical CoCr-E alloys include AWS A5.13 ECoCr-E or AWS A5.21 ERCoCr-E.

^h Manufacturer’s standard hardfacing with a maximum iron content of 25 %.

ⁱ Hardness diferential between the body and disc seat surfaces shall be the manufacturer’s standard.

^j Monel is used strictly as an example of any nickel-copper alloy 400 matching UNS N04400 specifcations. It does not constitute any endorsement of any specifc product or company by API.

^k Manufacturer’s standard with 30 Ni minimum.

^l Trim materials, including stem and base material for HF trim items, shall have a corrosion resistance and temperature limit at least equal to the valve body’s corrosion resistance and pressure temperature rating.

^m Per manufacturer’s standard if not hardfaced, 250 HB minimum if hardfaced

6.2 Trim

6.2.1 The trim comprises the following:
a) stem;
b) body seating surface;
c) disc seating surface;
d) bushing, or a deposited weld, for the backseat;
e) small internal parts that normally contact the service fuid, including split rings and other disc-to-stem retaining
components, are considered part of the trim.

6.2.2 The trim material, except as stated in a) through e) below, shall be the manufacturer’s standard materialfor the type listed in Table 8 for the trim number specifed in the purchase order. The typical specifcations included in Table 8 represent some acceptable grades.

a) If a trim number listed in Table 8 is specifed, then an alternative trim number as shown in Table 9 may be furnished with approval of the purchaser.

b) If a single trim (e.g. trim 5) is furnished, both the seating surface of the body seat ring and the seating surface of the disc shall be made of the type of material shown in Table 8.

c) If a combination trim (e.g. trim 8) is furnished, the seating surface of the body seat ring shall be made of one of the two types of material shown in Table 8, and the seating surface of the disc shall be made of the other type of material shown.

d) The stem, backseat, and stem hole guide, and the small internal parts (see 6.2.1 e) shall be of the type of material and hardness listed in Table 8. The stem shall be a wrought material.

e) Hardfacing of both the seat ring and disc seating surface is required for Class 900 and higher-rated valves.

6.2.3 The base material of the valve disc and separate body seat ring, when used, shall be of a nominal material composition at least equal to the body or to that of the stem material, except for disc material made of solid trim material as allowed by 5.6.4.