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.

DN	L	H	D‑1.0MPa	D‑1.6MPa	D‑2.5MPa	D1‑1.0MPa	D1‑1.6MPa	D1‑2.5MPa	N‑D 1.0MPa	N‑D 1.6MPa	N‑D 2.5MPa
50	205	300	160	160	160	125	125	125	4‑18	4‑18	4‑18
65	216	337	180	180	180	145	145	145	4‑18	4‑18	8‑18
80	250	467	195	195	200	160	160	160	4‑18	8‑18	8‑18
100	320	520	215	215	230	180	180	190	8‑18	8‑18	8‑23
125	365	580	245	245	270	210	210	220	8‑18	8‑18	8‑25
150	415	640	280	280	300	240	240	250	8‑23	8‑23	8‑25
200	500	778	335	335	360	295	295	310	8‑23	12‑23	12‑25
250	605	889	390	405	425	350	355	370	12‑23	12‑25	12‑30
300	698	1010	440	460	485	400	410	430	12‑23	12‑25	16‑30
350	787	1037	500	520	555	460	470	490	16‑23	16‑25	16‑34
400	914	1264	565	580	620	515	525	550	16‑23	16‑30	16‑34
450	978	1294	615	640	670	565	585	600	20‑25	20‑30	20‑34
500	978	1324	670	715	730	620	650	660	20‑25	20‑34	20‑41
600	1200	1600	780	840	840	725	770	770	20‑30	20‑41	20‑41
700	1450	1750	895	910	-	840	840	-	24‑30	24‑41	-
800	1560	1900	1015	1025	-	950	950	-	24‑34	24‑41	-
900	1800	2100	1115	-	-	1050	-	-	28‑34	-	-
1000	2000	2400	1230	-	-	1160	-	-	28‑34	-	-

Adjustable Pressure Reducing Valve

SLD200X Pressure Reducing Valve

Remote Control Float Valve

Safety Pressure Relief Valve