The orifice plate is basically a thin plate with a hole in the middle, which made of diversified materials, that include stainless steel, Carbon Steel etc.

The orifice plate usually device used for measuring the rate of fluid flow (both liquids and gases, fluid is considered as incompressible). It has been widely used in power plants, metallurgical industry, petrochemical industry and petroleum industry.

The thickness of the plate used ( 1/8-1/2″) is a function of the line size
orifice plate Standard:
ASTM/ASME/ANSIB16.5, B16.47, ASME/ANSIB16.48 flange
Size 1/2″-120″ (DN15-DN3000)
Pressure: Class150-Class2500
Facing RF/FF / RTJ
Standard: ASTM/ASME/ANSIB16.5, ASME/ANSI B16.3and B16.47, ASME/ANSIB16.42, JIS/KS (5K, 10K, 16K, 20K), DIN2633, DIN2634, DIN2635,EN1092,BS4504,AWWA C206,API 6A ,Customized drawings welcomed
stainless steel :A 182 F 304/304L/316/316L/321/347, Duplex F51/F53/F44/F55/F60/F61
Alloy steel :STM A694/ A694M F42/F46/F52/F56/F60/F70,A182  F5,F9,F11,F22
 Carbon steel:ASTM A 105, ST37.2   A 350 LF1, LF2, LF3,API 6A AISI 4130

stainless steel orifice plate