Class	150	300	400	600	900	1500	2500
Diameter - D	405	445	445	510	545	585	675
Height - B	28.6	46.1	54	63.5	69.9	108	165
	30.2	47.7	60.4	69.9	76.3	114.4	171.5
Diameter - G	323.9	323.9	323.9	323.9	323.9	323.9	323.9
Diameter - K	362	387.4	387.4	431.8	469.9	485	539.7
Bolt Holes	12	16	16	16	16	12	12
Diameter - L	25.4	28.6	31.8	34.9	38.1	50.8	66.7
Stud Bolts Diameter x Length
Diameter (in)	7/8	1	1.1/8	1.1/4	1.3/8	1.7/8	2.1/2
Length (mm)	115	160	190	215	235	335	490

Dimensional Tolerances of Blind Flanges ASME B16.5

Outside Diameter ≤ 24 = 1.6 mm | > 24 = ± 3.2 mm	Inside Diameter not applicable
Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm 6.35 mm Raised Face, Tongue & Groove / Male-Female = ± 0.4 mm	Outside Diameter of Hub ≤ 12 = + 2.4 mm / - 1.6 mm | ≥ 14 = ± 3.2 mm
Diameter of Counterbore not applicable	Drilling Bolt Circle = 1.6 mm | Bolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle with Respect to Facing ≤ 2.1/2 = 0.8 mm max. | ≥ 3 = 1.6 mm max.
Thickness ≤ 18 = + 3.2 mm / - 0 | ≥ 20 = + 4.8 mm / - 0	Length thru Hub ≤ 18 = + 3.2 mm / - 0.8 mm | ≥ 20 = + 4.8 mm / - 1.6 mm

Notes:
1. Dimensions are in millimeters unless otherwise indicated.
2. The length of the stud bolt does not include the height of the chamfers (points).


Welding Procedures & Welder Performance Qualification

Introduction

A welded construction applies, quality prescriptions concerning design production and use. Therefore clients in Petro and chemical industry claims approved welding procedures. Welding requires skill. Determining "how to weld" requires knowledge regarding the materials being welded and welding process, among numerous other factors. Because of huge number of variables involved, the knowledge of the welding engineer and the skill of the welder need to be validated by a series of tests.

This information is documented Section IX of the ASME Boiler and Pressure Vessel Code (BPVC), on:

1. Welding Procedure Specification (WPS)
2. Welding Procedure Qualification Record (WPQR)
3. Welding Performance Qualification (WPQ)