Question 1

What valves are used in water conservancy projects?

Accepted Answer

Water conservancy projects use a variety of valves depending on the application: (1) Large-diameter butterfly valves for water mains and penstock isolation (up to DN4000); (2) Gate valves (sluice gate valves) for water treatment plant channels and penstocks; (3) Check valves on pump discharge lines to prevent reverse flow and water hammer; (4) Hydraulic control valves for automatic pressure, flow, and level control in distribution networks; (5) Air release/vacuum valves for air pocket prevention and pipeline surge protection; (6) Flow control valves for precise flow regulation in irrigation canals and water diversion tunnels.

Question 2

What is a hydraulic control valve?

Accepted Answer

A hydraulic control valve is a pilot-operated, diaphragm-actuated valve that uses the line pressure of the water itself (hydraulic power) to operate — no external power source required. It can perform multiple functions: pressure reducing (maintaining constant downstream pressure), pressure sustaining/relief (protecting upstream pressure), float control (maintaining tank/reservoir level), flow control (limiting maximum flow rate), pump control (surge protection on pump start/stop), and solenoid override (remote on/off). Hydraulic control valves are widely used in municipal water distribution, irrigation networks, and fire protection systems.

Question 3

Why are air release valves needed in water pipelines?

Accepted Answer

Air release valves (also called air/vacuum valves) serve three critical functions in water pipelines: (1) Air release — automatically venting accumulated air pockets that form at high points, preventing flow restriction and energy loss; (2) Vacuum breaking — admitting air during pipeline draining or pump trips to prevent vacuum collapse of the pipe; (3) Surge protection — controlled air release during filling to prevent hydraulic surge. Without air valves, air pockets reduce pipeline capacity by 10-30%, increase pumping costs, and can cause pressure surges that damage pipes and fittings.

Question 4

What is the largest valve size TANGGONG can manufacture for water projects?

Accepted Answer

TANGGONG can manufacture butterfly valves up to DN4000 (4 meters / 160 inches) in diameter for water conservancy projects. These large-diameter butterfly valves are typically double-flanged, rubber or metal seated, and actuated by electric or hydraulic operators. They are used for water main isolation, penstock shutoff, and pump station suction/discharge in municipal water supply systems, irrigation projects, and hydropower stations. Custom sizes above DN4000 can be evaluated on a project-specific basis.

Question 5

What standards apply to water conservancy valves?

Accepted Answer

Key standards for water conservancy valves include: AWWA C504 (rubber-seated butterfly valves), AWWA C509/C515 (resilient-seated gate valves), AWWA C508 (swing check valves), AWWA C512 (air release, air/vacuum, and combination air valves), EN 1074 (valves for water supply — fitness for purpose requirements), EN 593 (industrial butterfly valves), GB/T 12238 (butterfly valves — Chinese national standard), and ISO 5752 (face-to-face dimensions for metal valves). TANGGONG manufactures to AWWA, EN, GB, and ISO standards per project requirements.

Item	1.0MPa	1.6MPa	2.5MPa
Shell test pressure	1.5MPa	2.4MPa	3.75MPa
Sealing test pressure	1.1MPa	1.76MPa	2.75MPa
The outlet pressure may adjust scope P2(MPa)	0~1.0	0~1.6	0~2.5
Working temperature	≤80℃	-	-
Applicable medium	Water, oil	-	-

DN(mm)	L(mm)	H(mm)
40	240	270
50	240	270
65	270	340
80	300	400
100	350	440
125	400	460
150	480	500
200	500	640
250	605	690
300	700	820
350	800	950
400	900	1150
500	1100	1550
600	1300	1600
700	1400	1750
800	1500	1900

Safety Pressure Relief Valve

Angle-type Remote Control Float Valve

Remote Control Float Valve

Safety Pressure Relief Valve