Brief Details of PVC Pressure Relief Valve for Canal Concrete Lining:

PVC Pressure Relief Valve is a device which allows water behind or below the structure to flow inside the canal or any structure but does not allow the water to leak back in the sub grade. These Pressure Relief Valves thus protects the lining or Structure from damage by releasing the excessive hydrostatic back pressure behind the lining or structure, especially when the canal lining or structure is subjected to drawdown or when the flow of water is suddenly closed.

Main Components

• PVC Weephole Fitment Assembly includes:
• PVC Silt Protector / Dome to prevent Rubber Flap from Silt and Exposure
• Metal Jali over the Silt Protector / Dome to give the assembly extra strength and security
• Specially designed injection molded PVC main plate with socket
• Rubber Flap with special Ring inside to prevent water from back leakages.
• Weight on the Rubber Flap encased in PVC Box.
• Non Corrosive Rivets and Fasteners.
• PVC Anchor Collar to join the Main Plate with Inverted Filter Box.
• An in built Inverted Filter Box filled with filter media inside.
• Nylon Jali inside the Filter Box and outside the Strainer Pipe, to prevent the perforations from chocking
• PVC brackets to hold the Nylon Jali on Strainer Pipe.
• PVC End Caps at one end of each, Filter Box and Strainer Pipe

Installation

As observed in case of PVC Pressure Relief Valves, the plate and rubber is fixed on strainer pipe over the canal lining and is therefore visible to everybody making it pilfer prone. Now Puraflex Weephole Fitment is installed 4-5 inches below the canal lining and over the Weephole fitment we have two options, either to refill the unfilled portion on top of the fitment with porous concrete or to place a perforated cement jail with wire mash and studs to make is undetectable.This porous concrete or cement jail is flushed with the canal lining surface. Both the options will make the fitment invisible to the common people (mainly miscreants) and hence eradicating the chances of pilferage and ensures the proper functioning of the required Weephole.

Advantages

• Minimum differential head required is less than half the head for which the lining can withstand safely i.e. minimum factor of safety of two is available.
• It is likely that when the channel / structure is running full and sub soil water table is low, back leakages may take place to the sub grade. For this safety of fitment is necessary, and with Weephole Fitment safety is ensured hence there are Zero chances of back leakages.
• All the components of Puraflex Weephole Fitment are abrasive resistant and will not be affected due to its presence in water.
• As weephole fitment is fitted almost 4-5 inches below the canal lining and perforated cement jali or porous concrete is  fitted or poured over it respectively, which flushes with the canal lining hence making it invisible to miscreants and ultimately make it pilfer proof.
• As the Weephole fitment is installed much below the canal lining, the entire assembly remains intact and all parts including the neoprene rubber flap remains functional resulting in proper discharge of sub soil water.This keeps the entire canal lining safe and strong.
• As the Weephole fitment is installed much below the canal lining, the entire assembly remains intact and all parts including the neoprene rubber flap remains functional resulting in proper discharge of sub soil water.This keeps the entire canal lining safe and strong.
• As the weephole is installed much below the canal lining, it remains protected all around. As it remains intact the chances of chocking are not there and hence the product remains functional.
• With PVC dome protecting the neoprene rubber flap the chances of silt deposition is almost negligible. The C value of PVC  is 155; hence there are no obstructions in the flow of water.
• Weight encased in PVC Box ensures that it keeps the rubber flap properly placed over the opening of the plate ensuring ZERO back leakages
• Nylon jali on both the filter box and strainer pipe ensures that the particle of filter media surrounding and inside the assembly does not choke the perforated portion of pipes, which removes the probability of chocking of weephole and you will get clean water on discharge.
• End cap at the bottom Filter box ensures that filter media / rubble do not enter the assembly along with the increase in sub soil water level. This eradicates the chances of chocking of weephole assembly.

Properties

SENSITIVITY
The PRV shall start functioning at the differential head of 10cm (IS: 4558-1983). But when tested according to the method Puraflex PVC PRVs are proved to be so very sensitive that they start working at the differential head of 2cm to 3cm.(Details of which can be taken on request).

DISCHARGE CAPACITY
The PRV Valve shall be capable of discharge at the maximum differential head of 15 cm.

SIZE	DISCHARGE
50 mm	400 cc to 500 cc per second
90 mm	750 cc to 850 cc per second
100 mm	1000 cc to 1100 cc per second
150 mm	1300 cc to 1400 cc per second

Back Leakages
The Back-leakage in Puraflex PVC PRV is ZERO.