Valve is the component that controls the fluid in the pipe and plays the roles of guidance, stop, adjustment, prevention of back flow and distribution of fluid. The valves used in the water supply and sewerage system are classified by usefulness and action. The main classification include block valves(mainly used in cut off or put through the medium, which include gate valve, stop valve, butterfly valve, ball valve and cock valve etc.), regulating valves( mainly used to regulate the flow rate and pressure of fluid, which include regulating valve, throttling valve and reducing valve etc.), check valves (used to prevent the back flow of medium, which include check valves of a variety of structures), delivery valves ( used to exhaust the air in the pipe automatically, which include single-port delivery valve and double-port delivery valve etc.). Every valve should be checked in factory. Type test is needed for some valves to verify if all the performances and functions can meet the standard of requirements for use.

2.Check and test items

 

See chart 1 and chart 2 for the check and test items of type test and factory test for valves for general use; See chart 3 and chart 4 for the check and test items of type test and factory test for regulating valves.

 

　　
Note:
① < Signify the items needed to check or test.
② Seal test should be made for the valve with sealing structure.

　　
Note:
① < Signify the items needed to check or test.
② Seal test should be made for the valve with sealing structure.

　　

　　


3.Standards of valve manufacturing and blank experiment

See chart 5 for manufacturing and inspection standards of valve of water supply and sewerage system.

 

Table 5 Value manufacturing and Inspection Standards

 

Standards No 　　　　　　Name of standards

Relative domestic standards
GB/T 1222021980 General purpose industrial valves--Marking
GB/T 1222121989 Metal valves for use in flanged pipe systems--Face-to-face and centre-to-face dimensions
GB/T 1222221989 Multi -turn valve actuator attachments
GB/T 1222521989 General purpose industrial valves-- Specification of copper alloy castings
GB/T 1222621989 General purpose industrial valves--Specification of flake graphite iron castings
GB/T 1222721989 General purpose industrial valves--Specification of spheroidal graphite iron castings
GB/T 1222921989 General purpose industrial valves--Specification of carbon steel castings
GB/T 1223021989 General purpose industrial valves--Specification of austenitic steel castings
GB/T 1223221989 General purpose industrial valves--Flanged iron gate valves
GB/T 1223321989 General purpose industrial valves--Casting iron globe valves and lift check valves
GB/T 1223421989 General purpose industrial valves--Flanged and butt-weld steel gate valves
GB/T 1223521989 General purpose industrial valves--Flanged steel globe valves and lift check valves
GB/T 1223621989 General purpose industrial valves--Steel swing check valves
GB/T 1223721989 General purpose industrial valves--Flanged and butt-weld end steel ball valves
GB/T 1223821989 General purpose industrial valve-- Flanged and wafer butterfly valves
GB/T 1224321989 Spring loaded safety valves
GB/T 1224421989 General specification for pressure reducing valves
GB/T 1393221992 General purpose industrial valves--Iron swing check valves
GB/T 1417321993 Specification for hydraulic flat steel gates
GB/T 1518521994 Cast iron and copper alloy ball valves
GB/T 846421998 Valves with female screw ends for water-heating system
JB 30821975 Valve--Method of type designation
JB/T 529921998  Hydraulic controlled check valve
B/T 792721999 Requirements for appearance and quality of valve steel castings
JB/T 792821999 General purpose industrial valves—Requirements for product supply
JB/T 852721997 Metal sealed butterfly valve
JB/T 852821997 Specifications for electric devices of ordinary-type valves
JB/T 853121997 Specifications for manual devices of valves
JB/T 869121998 Wafer-type knife gate valves
GB/T 1392721992 General purpose industrial valves—Pressure test
JB/T 529621991 General purpose industrial valves—Test methods for flow factor and factor of flow resistance