Durga Valves Pvt. Ltd.

Ichapur, Howrah, West Bengal

2800mm HOPD* Butterfly Valves DVPL has successfully designed, manufactured, tested and offered to TPIA as per AWWA C516-10 on 10th March 2017. DVPL's Research and Development wing has developed complete HOPD range up to 4000mm BFV's as per national and International standards.

Salient design features of high end HOPD BFV product are as follows:
Hydraulic drive from both ends for enhanced stability of performance
Zero maintenance product.
Having Nitrozen gas back up in cryogenic state.
Sturdy Box-Type cylinder mounting also enabling enough space for various instrumentations
Body mounted cylinder away from Floor mounted design
All feedbacks from the valve are provided and can be controlled from a Centralized Command Centre

* HOPD: Hydraulically operated pump discharge valves are actuated with a hydraulic power-pack and single-acting cylinders. The linear stroke of the cylinder is converted into 900 rotary movement of the valve disc. Auxiliary support are provided for open/close of valve disc in a controlled manner. In the case of an emergency, the valve disc can be closed using the force of gravity acting on the mounted counter-weights.

We also having flexible type design to meet the enhanced customer special requirements and to meet the dynamic site situations.

DVPL is having 40 years of sound experience in manufacturing and supplying of actuator operated Butterfly valves. DVPL offers complete range of butterfly valves. DVPL's Research and Development department has developed India's best product by lesser operating torque. DVPL is only company offering ZERO leak products in metal to metal Butterfly valves. DVPL installs internationally approved actuator's brands one is AUMA and the other is Rotork. DVPL maintains the 0.05 micron between two ends of operation. Due to high accuracy in production and components our operating torque is lesser and life of the valve and actuators are 50% more than other competitors which made us to stand tall in this variety.

The valve combines small and large orifices. It consists of a specially designed single small orifice valve and a single large orifice valve, with modified bodies to allow bolting together and free flow between them. The small orifice valve comprises a Stainless Steel float with polymer guide and rolling seal mechanism to seal the small orifice vent. When the large orifice float chamber is filling with water, the orifice is closed initially by the float. When the large orifice chamber is filled with water under pressure, the orifice is held closed by the combined up thrust of the float and the differential pressure over the orifice area. On air accumulated in the system entering the chamber under working pressure, the water level in the small orifice chamber is depressed until it reaches a point when the weight of the float is sufficient to uncover the orifice and exhaust air. Air is expelled until the water level rises again in the small orifice chamber and causes the float to close the orifice. The large orifice valve consists of a sealing off a large orifice vent to the atmosphere. The float is held at a predetermined height in its casing by specially designed cage which also guides the float onto the seat. During pipeline filling or emptying, the Aerodynamic feature holds the float off the seat and keeps it completely stable under all air outflow or inflow conditions. The valve cannot close prematurely during outflow. It closes only when water enters the casing and raises the float onto the seat.

DVPL offers complete rage of resilient seated butterfly valves wafer type, lug type, Double flanged, Full flanged, Bi directional and tight shutoff at elevated temperatures and pressures. We offer high Cv and lower pressure drop valves

DVPL is having 40 years of sound experience in manufacturing and supplying of actuator operated Butterfly valves. DVPL offers complete range of butterfly valves .DVPL's Research and Development department has developed India's best product by lesser operating torque. DVPL is only company offering ZERO leak products in metal to metal Butterfly valves. DVPL installs internationally approved gear units. DVPL maintains the 0.05 micron between two ends of operation. Due to high accuracy in production and components our operating torque is lesser and life of the valves and actuators are 50% more than other competitors which made us to stand tall in this variety.

DVPL make Sluice Valves widely accepted by Municipal Corporations, Irrigation authorities, Water supply authorities and other Government and Industrial users. They are designed as per latest editions of IS Standard bearing ISI mark for Rising Spindle Sluice Valves.

DVPL gate valves (Soft seated) Resilient soft seated gate valves with body bonnet of DI of grade GGG40/GGG50, wedge fully rubber lined with EPDM and seals of NBR and valve should be 100% leak proof with face to face dimension as per BS-5163-89

DVPL offers Single Door Non Return valves are very useful in preventing back flow of water to the pump. These valves have minimum head loss and can be very competitive in terms of long service life. These valves are very useful in waterworks pipelines to reduce hammer effect.

T-type Globe Valve design is the most common body type, with a Z-shaped diaphragm. The horizontal setting of the seat allows the stem and disk to travel perpendicular to the horizontal line. This design has the lowest coefficient of flow and higher pressure drop. They are used in severe throttling services, such as in bypass lines around a control valve. Tee-pattern Globe valves may also be used in applications where pressure drop is not a concern and throttling is required.

Ordinary spring loaded pressure relieve valves which open at a predetermined pressure are of no use in relieving the high surge pressures encountered during in Water Hammer.

The main reasons are that they are extremely slow in opening and they close down when they encounter a negative pressure. The Water Hammer surge consists of a series of quickly alternating waves of very high pressure and low pressure.

To counter the Water Hammer surge what we need is a valve that opens quickly and sucks in air into the pipeline but does not allow this air to escape on encountering a positive pressure wave. The slow closing ensures that the subsequent positive pressure waves are damped by the action of the entrapped air.

In our Air Cushion Valve, the quick opening is achieved by a spring loaded air inlet port. The spring is designed to open at a preset pressure differential. The slow closing is achieved by using an orifice to expel the air at a controlled pressure and rate. The orifice effectively behaves like a pneumatic damper. By adjusting the setting of the orifice, we can control the outflow rate of air from the valve.

All moving parts (shafts, bushes and stoppers) and the entire needle orifice are made of Stainless Steel. The rest of the body is a modular mild steel fabrication. The modular design allows for easy maintenance.

The sizes of ACV valves depend on the pipe diameters in the following manner:
ACV - 100 : up to 300 mm. pipe dia.
ACV - 150 : From 300 to 400 mm. dia.
ACV - 200 : Above 450 mm. dia.

DVPL make Sluice Valves widely accepted by Municipal Corporations, Irrigation authorities, Water supply authorities and other Government and Industrial users. They are designed as per latest editions of IS Standard bearing ISI mark for Non Rising Spindle Sluice Valves.

DVPL offers complete range of resilient seated butterfly valves wafer type, lug type, double flanged, full flanged, Bi directional and tight shutoff at elevated temperatures and pressures. We offer high Cv and lower pressure drop valves.

Air venting for small pockets of air release from pressurized piping system
2. Air/vacuum for large air exhaust during filling of the pipeline and
3. Admitting large volumes of air during draining of piping system.

Features:
Advanced design with simple mechanism, strong float to prevent cracking during sudden water hammer.
The float will still be at bottom level even up to air velocity about sonic velocity, until water rises to lift the float and seal the orifice.
No arms or levers to prevent vibrating, direct closure of the float.
Smooth cage outside of the float, keep float moving in specified guide rail.
Bottom impact rubber for collision prevention, and drain easy with proper holes around during vacuum.
Outside screen will be an option for safety and prevent insects or birds in.
Fully fusion epoxy coated inside and outside of valve body for long term services.
Manufacturing standard meets BS EN 1074-3, AWWA C512
Flange drilling and dimension meets IS 1538 and BS EN 558.

Service Fields:
For water system, fire fighting, irrigation System.

Technical Data:
Size Range: DN 50-200MM
Pressure ratings: 1.0Mpa, 1.6Mpa, 2.5 Mpa.
Working temperature: -10-80C.
Flow media: clean water
End Connection: PN10/16/25.

DVPL Multi Door Non Return Valves conform to IS 5312, Part-2 standard for dimensions, materials of construction and constructional features, as per the need of the application. The doors of the Multi Door Non Return Valve are hinged on Diaphragm. Door Rings and Diaphragm Rings are precisely machined, Ground, Lapped to get required finish for achieving zero leak tightness. Number of Doors are two for sizes 600 to 800mm, three for sizes 900 & 1000mm and four for sizes 1100 & 1200mm, For 2000mm eight doors design. By-pass arrangement is provided at specific requirement from customer, and the s

DVPL Resilient Seated Check Valve is of lightweight design and construction of ductile iron for durable extended life performance. Valves can either be used above ground or buried service applications and are maintenance free.

DVPL offers entire verities of knife edge gate valves which include Bolted Bonnet metal seated; Bolted bonnet resilient seated, Standards metal seated, Standard resilient seated End connection will be lug type & lug type. We offer casted valves and fabricated valves. DVPL offers Hand wheel operated valves, Gear Unit operated valves and Actuator operated valves.

DVPL Foot Valve widely accepted by Municipal Corporation, Irrigation Authorities, Water Supply Authorities, National Thermal Power Corporation and Industrial users. Designed as per latest editions of IS 4038 specifications.

APPLICATIONS
Footer Valves are installed in suctions side of the pumps to avoid flow reversal from pump to the sump, in order to maintain pump priming. They also prevent entry of foreign particle into pump through suction pipe. These valves are suitable for having clear water within the limits specified by IS:4038.

SPECIAL FEATURES
Excellent design features Right and sturdy design with minimum loss of head across the valve. Perfectly flat seating faces for good sealing. Long service life.

Angle Pattern Globe Valves design is a modification of the basic Tee Pattern Globe valve. The ends of this Globe valve are at an angle of 90 degrees, and fluid flow occurs with a single 90 degrees turn. They have a slightly lower coefficient of flow than wye-pattern Globe valves. They are used in applications that have periods of pulsating flow because of their capability to handle the slugging effect of this type of flow.

Y-type Globe Valves design, is an alternative for the high pressure drop, inherent in Globe valves. Seat and stem are angled at approximately 45 degrees, what gives a straighter flowpath at full opening and offer the least resistance to flow. They can be cracked open for long periods without severe erosion. They are extensively used for throttling during seasonal or startup operations. They can be rod through to remove debris when used in drain lines that are normally closed

DVPL offers versatile design with 80% lesser weight than the conventional type swing check valves.
Simplifies piping.
Reduces thermal and seismic considerations.
Optimizes space utilization.
Lower installation costs.
Reduces pipe supports requires less number of man-hours.
Duel discs open to 85 degrees.
Low cracking pressure and overall pressure drop Ensures positive closure.
Spring-loaded discs calculated to increase the responsiveness of the discs.
Alleviates water hammer and resultant damaging effects.
Extended long- leg spring.
Prevents seat wear caused by scrubbing

The Anti-Vacuum Valve is a one kind of air valve. Main function is to prevent the formation of vacuum in hydroelectric penstocks and large diameter water main

DVPL Foot valve is a kind of energy-saving valve, usually installed at the bottom of pump suction pipe to prevent medium in the pipe flow back to water source. There are many inlet holes and reinforcing ribs in the valve cover, so the pipe will not be easily clogged up.

DVPL Research and Development wing has developed unique characteristic product to meet the dynamic site situations. We cover entire product range.