VAISHNAVI HYDRAULICS PVT. LTD.

CHECK VALVE OR NON RETURN VALVE

Designation & Symbol – CV

Check valves are also known as Non Return Valves
Check valves are self-activating safety valves that permit gases and liquids to flow in only one direction, preventing process flow from reversing.
They are classified as one-way directional valves.
Fluid flow in the desired direction opens the valve, while backflow forces the valve closed.
The mechanics of check valve operation are relatively simple.
Most check valves contain a ball that sits freely above the seat, which has only one through-hole.
The ball has a slightly larger diameter than that of the through-hole.
When the pressure behind the seat exceeds that above the ball, liquid is allowed to flow through the valve; however, once the pressure above the ball exceeds the pressure below the seat, the ball returns to rest in the seat, forming a seal that prevents backflow.
Check valves use a variety of technologies to allow and stop the flow of liquids and gases.
Single-disc swing valves are designed with the closure element attached to the top of the cap.
Double-disc or wafer check-valves consist of two half-circle disks hinged together that fold together upon positive flow and retract to a full-circle to close against reverse flow.
Lift-check valves feature a guided disc.
Spring-loaded devices can be mounted vertically or horizontally.
Silent or center guide valves are similar to lift check valves, with a center guide extending from inlet to outlet ports.
The valve stopper is spring and bushing actuated to keep the movement "quiet".
Ball check valves use a free- floating or spring loaded ball resting in a seat ring as the closure element.
Cone check valves use a free-floating or spring loaded cone resting in the seat ring as the closure element.
Selecting check valves requires an analysis of performance specifications, materials of construction, connection types, and media.
Performance specifications include valve size, pressure rating, media temperature, and valve flow coefficient.
Most check valves are made of acetal polymers, aluminum, brass, bronze, cast iron, chlorinated polyvinyl chloride (CPC), ductile iron, copper, polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), rubber, steel, or stainless steel.
Connections for check valves can use threads, compression fittings, tube fittings, bolt flanges, clamp flanges, butt welds, socket welds, and union connections.
In terms of media, check valves are rated for air, compressed air, water, hot water, cold water, potable water, salt water, wastewater, gasoline, diesel fuel, high-purity gas, liquefied petroleum gas (LPG), natural gas, sour gas, corrosive gas, abrasive material, acids, corrosive chemicals, adhesives, concrete, grout, coolants, hazardous materials, high-viscosity fluids, hydraulic fluids, liquid metal, lubricants, oil, powders, solids, rendering wastes, sludge, slurry, ash slurry, or steam.
Check valves are available in Steel, Stainless Steel, Brass Materials & can be applicable for Low pressure Application, High pressure Application & for water.

Check Valves	Series		Sizes For Threads	Types of Threads Available
Needle valves with Female Threads	3000	6000	1/4" up to 2"	BSPP/BSPT/NPT/UNF
Needle valves with Male Threads	3000	6000	1/4" up to 2"	BSPP/BSPT/NPT/UNF
Needle valves with Metric Tube Od	3000	6000	6 mm upto 42 mm od	Metric Threads with Nut + Ferrule
Needle valves with UNF Tube Od	3000	6000	1/4" od up to 2" od	UNF Threads with Nut + Ferrule
Check valves with Tube to Thread End	3000	6000	6 mm upto 42 mm od	Metric to Bspp threads

Non Return Valves - Tube to Tube End	W.P.- BAR	Series	Sizes For Threads	Types of Threads Available
6 MM to 15 MM OD	250	Light	6 MM to 15 MM	Metric Threads both end
18 MM to 22 MM OD	160	Light	18 MM to 22 MM	Metric Threads both end
28 MM to 42 MM OD	100	Light	28 MM to 42 MM	Metric Threads both end
6 MM to 12 MM OD	630	Heavy	6 MM to 12 MM	Metric Threads both end
14 MM to 25 MM OD	400	Heavy	14 MM to 25 MM	Metric Threads both end
30 MM to 38 MM OD	250	Heavy	30 MM to 38 MM	Metric Threads both end

Non Return Valves - Tube to Tube End	W.P.- BAR	Series	Sizes For Threads	Types of Threads Available
1/8" od up to 2" od Tube Size	400	Heavy	1/8" up to 2"	UNF Threads both end
6 mm up to 50 mm od Tube Size	400	Heavy	6 mm up to 50.8 mm	UNF Threads both end

Non Return Valves - Tube to Male End	W.P.- BAR	Series	Sizes For Threads	Types of Threads Available
6 MM to 15 MM OD	250	Light	6 MM to 15 MM	Metric X Bsp Threads
18 MM to 22 MM OD	160	Light	18 MM to 22 MM	Metric X Bsp Threads
28 MM to 42 MM OD	100	Light	28 MM to 42 MM	Metric X Bsp Threads
6 MM to 12 MM OD	630	Heavy	6 MM to 12 MM	Metric X Bsp Threads
14 MM to 25 MM OD	400	Heavy	14 MM to 25 MM	Metric X Bsp Threads
30 MM to 38 MM OD	250	Heavy	30 MM to 38 MM	Metric X Bsp Threads

CHECK VALVE OR NON RETURN VALVE

CHECK VALVE OR NON RETURN VALVE

Designation & Symbol – CV

Materials

Non Return Valves - Tube to Tube End - For Hydraulic Applications

Non Return Valves with tube to tube end connection are available in below types & sizes

Materials

Non Return Valves - Tube to Tube End - For Instrumentation Tube systems

Ball Valves with tube to tube end connection are available in below types & sizes

Materials

Non Return Valves - Tube to Male End - For Hydraulic Applications

Non Return Valves with tube to Male Thread end connection are available in below types & sizes

Materials