2.4 article 6.3.3 the pressure pump shell shall be designed as follows:

a) Under the worst combination of the maximum allowable working pressure (and maximum working temperature) and twice the allowable nozzle load on each nozzle listed in Table 5, there shall be no leakage in operation or no contact between rotating parts and stationary parts.

b) It can withstand hydraulic test.

[interpretation] in practical application, for some special occasions or important working conditions, some users require that the pump can meet the allowable nozzle load of 2.5 ~ 4.0 times on each pipe orifice listed in Table 5. At this time, the pump shell, pump foot and base shall be designed with heavy load, which undoubtedly will greatly increase the manufacturing cost of a single pump. In this case, it is necessary to fully communicate with users to reach a solution acceptable to both parties.

2.5 article 6.3.7 additional corrosion allowance shall be considered in the design of pressure pump shell to meet the life requirements in article 6.1.1. The minimum corrosion allowance shall be 3 mm unless otherwise specified.

[interpretation] in practical application, for class 2 and 3 process pumps or chemical pumps with low pressure, in order to reduce the cost, many domestic users rarely strictly implement it

2.6 article 6.3.10 radial split pump shell shall adopt metal to metal contact fit, and the middle is clamped with constrained compression pad, such as O-ring or metal wound gasket.

[O-ring is not widely used in engineering practice.

2.7 article 6.4.3.5 welding of all joints (connected to pump casing) shall be completed before hydrostatic test of pump casing.

[interpretation] there are two meanings: 1) the connecting pipes on the shell (such as liquid drainage, exhaust and sealing flushing) are required to be connected by welding; 2) before hydrostatic pressure test, the welding work of all nozzles has been completed. At the same time, nondestructive testing should be carried out at the weld to ensure no leakage during operation.