Butterfly Valve EUROSTOP - Buried type

Butterfly valves are isolating valves used on water supply networks, in the interconnections of network, in the factories, in pumping stations, on the general networks and on the fire protection networks in the industrial sites.

Butterfly valves are compatible with drinking water and raw water with grid filtration. They will be installed on water networks in factories, in valves chambers or buried.

Their main advantages are: 

• Low pressure loss

• Good performance thanks to the choice of the materials, the coatings and the design

• Easy operation per mechanism of the worm type/without end

• Mechanisms equipped with a standardized flange carry-accessory for buried version and motorizable version

Hydraulic test

Every single butterfly valve is subjected to hydraulic final test with the purpose of verifying the accordance with the prescriptions ISO 5208:

• Body test at 1,5 time the PFA (open valve);
• Seat test at 1,1 time the PFA (closed valve).

Product test

• Control of manoeuvre torque (MOT and mST) as defined in the EN1074
• Control of coating: test of thickness, holiday test, impact test, MIBK test

Conformity to the standards

Product:

• EN 1074 – 1 and 2
• EN 593
• ISO 10631

Plant test:

• ISO 5208

Flanges dimension:

• ISO 5752 series 14

Flanges drilling:

• EN 1092-2
• ISO 7005-2

Suitability for potable water:

• Italian CM 102 of 02/12/78
• Conformity to foreign norms: KTW (Germany), WRC (U.K.), ACS (France)

On the body like EN19:

• Nominal diameter in mm (DN);
• Nominal pressure in bar (PN);
• Type of ductile iron;
• Manufacturer’s logo;
• Model code;
• Fusion date.

On the label like EN19:

• Nominal diameter in mm (DN);
• Nominal pressure in bar (PN);
• Maximum operating pressure (PFA);
• Closing direction;
• Model code;
• Manufacturing order, Order confirmation;
• Manufacturer’s logo.

On the disc:

• Nominal diameter in mm (DN);
• Nominal pressure in bar (PN);
• Type of ductile iron;
• Manufacturer’s logo;
• Model code.

The marking of the valves manufactured by Saint-Gobain refers to the EN 1074-2 and EN 19 international standards.

Markings are either integral markings, cast in the body, or markings made on plates, securely fixed to the body, in accordance with the EN 19 standard specifications.

The head loss Δh are variable in function of valve open degree and can be calculated with the following expression:

with Δh = head loss (m), ζ = head loss coefficient (dimensional), v = nominal speed (m/s), g = 9,81 (m/s²)

The head loss coefficient can be estimated from the diagram attached.

Determinates the head loss Δh it’s possible to calculate the flow rate Q in m3/h with the following expression (the same expression can be used to, having the project flow rate Q, to determinate the head loss Δh without using the head loss coefficient):

in which 10,2 is a corrective factor in meters, and Kv is the flow rate coefficient in m3/h, determinable from the following diagram in function of valve open degree:

Example: Valve DN600 mm - Δh = 3 m

From the diagram with valve open to 100% the coefficient Kv is 20000 m3/h. Using this date in the flow rate expression:

Otherwise it’s possible to calculate the head loss with valve completely open, having the project flow rate Q, in function of DN, using the following diagram:

Cavitation

If the butterfly valve is used only like isolating device there’s not cavitation risk.

In the particular case in which it’s used like regulating device, this can be possible only respecting the following parameters:

• The valve open degree have to be between 30° and 90° (valve completely open)

• The downstream pressure P2 have to be: P ≥ 0,7 .P - 2,8 with P upstream pressure.

Storage

The butterfly valve will have to be held (if possible) in covered places, the most possible protected from the sun (maximum allowable temperature 70°C in accordance to EN 1074), from the rain and generally from the atmospheric agents. Moreover it will have to be avoided that the seal of the same air valves come to contact with powder or earth.

Installation

The butterfly valves are generally installed with retaining ring mounted in the opposite way respect to the direction of flow rate to permit the substitution of gasket without dismounting the valve from pipeline. In any case it is possible to install the butterfly valve with flow rate in opposite direction and also, if required, in vertical position. We recommend to install the butterfly with the operating device on the hydraulic right side of pipeline.

It’s possible to install the butterfly valve both in chamber valve that underground (choosing the right configuration).

We recommend to insert a dismounting joint for the operation of maintenance.

Maintenance

The butterfly valve does not require a particular maintenance, all parts subjected to wear are perfectly auto-lubricating. In any case, if for a long time will be not used, it is necessary to evaluate the functioning of valve doing (at least one time for year) some manoeuvre of opening-closing.

All the maintenance operation have to be do after the total emptying of pipeline (no flow rate and pressure) to avoid every risk to the people during this operation.

In presence of particularly exercise condition or damage due to external cause, it will be necessary some maintenance operation. In this case the particular shape of EUROSTOP butterfly valve permits the simple gasket substitution without the dismounting of valve from pipeline (if the dismounting joint is present).

Accessories

To adapt the butterfly valves to the different exercise and installation conditions required, they can be equipped with particular accessories used in combination with control devices: please refer to data sheet for accessories.

The technical features in this document are not contractual and can be changed without preliminary notification due to the continuous technical progress of product.

The butterfly valves are generally used as isolating devices type on/off. In some particular case, in which there’s low differences of pressure and low flow rate variation can be used like regulating devices, considering the hydraulic parameters necessary to avoid the cavitation risk.

To do the right dimensioning of butterfly valve it’s necessary to know the followings parameters:

• Upstream hydrostatic pressure (that is the hydrostatic pressure with valve in closed position)
• The maximum speed in water pipe (generally expressed in l/s) or the nominal diameter and the project flow rate from which it is gained the speed V=Q/A

Moreover it’s necessary to control that the maximum speed in water pipe have to be equal or inferior to 5m/s, and the exercise temperature have to be between 0°C and 40 °C.