nrv valve

nrv valve Material: Composite Material Size: DN50-3000 Less weight Long service life

 nrv valve

Structure and operating principle   of valves and fittings :

 it's composed of valve seat, valve plate, consolidated soil seal ring, hinge four parts.

Only be used to single-track water of round or square water outlet, it has advantage of strict structure, good reliability and operate need not the force of people. Motive power of start and stop come from the pressure of water. When the inside pressure greater than outside, the flap valve will open, conversely, it will close.

 

The nature of nrv valve :

 

Nominal pressure: 0.1MPa-1.0MPa

Applicable media: water, river water, seawater, living water, industrial sewage.

Applicable temperature: <50°C

 

Applicable scope:

water conservancy system, municipal wastewater, flood control works, sewage treatment plant, waterworks and so on.

 

The specification and category:

The specification of relief valve is divided into round and square two kinds, it can be designed and produced depend on the form of the water outlet.

The relief valve has two categories: hollow floating plate shape and flat plate shap.

 

 

FRP nrv valve mechanical property reference table

 

1.direction elastic modulus	2.direction elastic modulus	shear elastic modulus	Poisson's ratio	tensile strength of 1,2 direction 1,2
10GPa	10GPa	4GPa	0.25	120MPa

 

 

The performance of  nrv valve

Item/material	FRP flap valve	Steel flap valve	Cast iron flap valve	HDPE flap valve
tensile strength (MPa)	160-320	380	187	21
Specific strength	100-168	48.5	25.5	22
specific gravity	1.8-2.1	7.84	7.34	0.954
Opening water level   (mm)	>20-50	>150	>150	>50
Opening angle	>60°	<50°	<50°	>60°
corrosion resistance	Resist	no resistant	no resistant	Resist
ageing resistance	Resist	Resist	Resist	Resist
Seal condition	Well	Well	Bad	Well
Maintain and replace	General maintenance-free	make once corrosion prevention every year	make once corrosion prevention every year	General maintenance-free
Theftproof condition	Without recycling value	easy be stolen	easy be stolen	easy be stolen

 

Install of nrv valve :

 

1.     sanitary valves valves can be installed in the following ways: flange connection and concreting.

2. The distance of the centre of howell bunger valves and flow centre allowable deviation is not greater than 3.0mm.

3.   sanitary valves all around should be left 400 mm installation space, below the export of flap valve, there is made a slop of 1:5.

4. Install fitting: bolt or expand silk use stainless steel or carbon steel through antiseptic treatment; seal fitting use rubber or rubber gasket.

FRP   sanitary valves installation requirements:

 

Flange connection type sanitary valves divide into wing ring tube flange connection type, embedded bolt flange connection type and expand screw flange connection type three kinds.

1. Wing ring tube flange connection type:

When make sanitary valves , put the wing ring tube with flange pouring on the water outlet place. Flange and basic face should be parallel, fix the flap valve after solidify of concrete. (Applicable to below DN1000)

nrv valve