Where bonnets or covers are joined to valve bodies by means of bolting,
bolting shall be threaded in accordance with ASME B1.1 for inch dimensioned bolting or ASME B1.13M for metric bolting and,
as a minimum, shall satisfy the following bolt cross sectional area requirements:
Ab: total effective bolt tensile stress area
Ag: area bounded by the effective outside periphery of a gasket or O-ring or other seal-effective periphery,
except that in the case of a ring-joint the bounded area is defined by the pitch diameter of the ring
K1: 65.26/MPa when Sa is expressed in MPa units or .45/psi when Sa is expressed in psi units
Pc: pressure rating class designation i.e. 150, 300, 600, 900, 1500
Sa: allowably bolt stress at 38 degrees C (100 degrees F), MPa (psi). When greater than 137.9 MPa (20,000 psi), use 137.9 MPa (20,000 psi.)
The allowable stress values shall be taken from the ASME Boiler and Pressure Vessel Code, Section II, Part D using the listings for Section VIII, Division 1,
or Section III, Division 1, Class 2 or Class 3. This algebraic expression requires that a consistent set of units be used.
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| Ag | |
| Ab | |
| Pc | |
| sealing diameter | |
| bolt major diameter | |
| threads per inch | |
| number of bolts |