LF825Y- Reduced Pressure Zone Assembly is a lead free, bronze body device designed to protect against hazardous fluids in water supplies to industrial plants, morgues, chemical plants and hospitals.  They can also be dual used in irrigation circuits, water lines and other installation requiring maximum protection.  The device comes in sizes 20-50 mm.  The working pressure is 175psi.

Draining the tank : The tank is drained using the safety valve which can be activated manually, and once opened, the water held under pressure in the tank is drained out. (Caution : make sure that the electrical connection of the tank has been previously disconnected. In addition, take precautions against burns during hot water drainage). The drainage outlet on the Safety Unit, which comprises an air gap preventing any backflow of the drained water, should be connected to the drainage system.

Flomatic

Preventing a backflow of cold water into the cold water supply system : A check valve prevents any backflow of hot water (which is under pressure in the tank) into the cold water supply system, as soon as the pressure in the tank becomes higher than that of the cold water supply.

We do not allow our safety groups to be used on installations of hot water tanks in series or in parallel. Our safety groups have the advantage of a French standard right of use (NF EN 1487 NF-D 36401) and are thus intended, like all NF safety groups, for connection to a household cold water supply. For installations using an installation of hot water tanks in series, we recommend the installation of household safety valves with a setpoint conforming to the water tank manufacturer’s recommendations. For solar installations, there are valves that are specially adapted for high temperatures (WATTS SV/E model).

Isolating the hot water tank from the cold water supply : This function is carried out by the stop valve (also part of the Safety Group).

F - The safety group installed on 2 hot water tanks in series or in parallel (frequent in solar installations) is very hot. Is this normal?

If you have a pressure reducer on your installation (where you water supply enters the house or near the hot water tank), it is usually set to 3 bars. Thus, each time you open a hot water tap, you make the pressure drop in the tank and bring the mains water back up to 3 bars. Check this when the safety group is flowing, by opening a hot water tap and finding that the valve flows less and then not at all.

It is necessary to have one or several anti-hammer devices installed as near as possible to the appliance causing the water hammer (single-control mixer tap, push-handle taps, washing machine solenoid valve, 1/4 turn taps, etc.). We recommend the choice of pneumatic anti-hammer devices that are more efficient than the spring models.

When a water hammer happens, the safety group might open to release a little water. When this happens, at the same time, a few particles in the water can be trapped between the valve facing and the elastomer membrane, thus causing a leak.

Febco765

No. As explained above, to compensate for the expansion of the water, for 7 bars, the safety group opens to let a little water flow out and thus to compensate for the expansion of the water. We should find a trickle of water in the form of regular drops, corresponding with an average of 3% of the volume in the tank. If there is a significant and permanent flow, the supply pressure of the network is too high at night (frequently due to lower water consumption at night). It is then necessary to install a water pressure reducer (REDUFIX type) near the safety group. It is also possible to install an expansion vessel that will absorb the expansion of water and avoid too great an opening of the safety group (see WATTS expansion vessels and WATTS connection kit, art. 2292504N).

The safety group closes its non-return valve and thus impedes any return of hot water into the cold water supply circuit. This is the non-return function of the safety group. To compensate for the expansion of the water, for 7 bars, the safety group opens to let a little water flow out and thus to compensate for the expansion of the water. It is therefore normal to find a trickle of water in the form of regular drops (corresponding with an average of 3% of the volume in the tank).

D - What should I do if the safety group flows all the time? This fault is due to there being a foreign body that prevents the valve from closing, or by the water being too corrosive or aggressive - and which damaged the safety group beyond repair.

It is usually a grain of sand, scale or a copper / brass shaving when work is being done on the plumbing or the installation. These particles stick to the elastomer membrane of the valve and prevent the membrane from sealing against the valve face. If the particle is not deeply embedded, you can try to remove it by opening the safety group knob completely. Otherwise, call a professional plumber and have him dismantle the valve with a special tool and clean the membrane. If the elastomer membrane is damaged or too deeply marked, the valve module should be changed or even the whole safety group. These particles do not always come from the mains water and can come from sediment or particles of scale that form in the hot water tank with time. Unfortunately, installing a sediment filter does not solve this type of problem completely.

FEBCO

In the present installations, the use of increasing numbers of fast-closing appliances (single-control mixer tap, push-handle taps, washing machine solenoid valve, 1/4 turn taps, etc.) aggravate this phenomenon. These are the cause of a significant increase of water hammers, leading to: • Rapid wear of equipment, sometimes even their sudden deterioration. • Noises that do not comply with the present acoustic standards. • Damage to the pipes and risks of leaks at the joints.

The SFR, SFR STAINLESS STEEL, SFR angle body STAINLESS STEEL, and GSM 1" STAINLESS STEEL safety groups comply with standard NF-EN 1487 and have the advantage of the right to using the NF mark (NF EN1487 NF-D 36401).

860U- Reduced Pressure Zone Assembly this Febco device is designed with union ended ball valves which allows the backflow prevention expert to remove and service the device without the requirement to turn off the main water supply or the device can be replaced with minimal down time due to its quick connection of its union ended ball valves.  The backflow prevention device is testable with a high hazard rating and a working pressure of 175 maximum psi.  The available are from 15-50mm.

• The stainless steel seat eliminates the risk of corrosion and any problems with the valve. • The body of the SFR STAINLESS STEEL valve is equipped with a flat section above the drainage, which facilitates its installation and fitting direction. • The valve, in the form of a removable module, can be changed with a special wrench (tool reserved to professional plumbers), without having to dismantle the entire valve unit. • Its STAINLESS STEEL valve seat is practically invincible to all water qualities. Once the valve is dismantled, it is easy to clean the facing and re-screw the valve module. The safety group is immediately operational again.

A - Every evening at the same time, the safety group installed on the hot water tank leaks. Is this normal? Yes, if the flow occurs whilst the tank is heating, and about 30 minutes after the end of the heating cycle. This is normal and the expected function by this safety component, which is the safety group. This leak is due to the increase of volume by the expansion of water that is heated by the electrical immersion resistor in the tank. When water heats up, its volume increases, as does its pressure.

Protecting the hot water tank from pressure excess : As the water temperature increases, the pressure also increases inside the water tank (dilation of the water). For safety reasons, this pressure must be restricted to a value lower than the tank's safety pressure. This function is carried out by the safety valve which is set at 7 bars.

I – Which safety group should I choose for which water quality? The hardness of water in France is expressed in concentration by weight degree of hardness. One TH of 1°F (French degree) is equivalent to 10 grams of limestone per cubic metre. Soft water is more aggressive and therefore more corrosive than hard water. Hard water leaves more solid scale, which clogs appliances and degrades the water tightness of equipment. For this reason, a removable and interchangeable valve is an advantage.

H - What is the difference between a standard safety group and the SFR STAINLESS STEEL? The SFR STAINLESS STEEL safety group is an upmarket appliance, the result of many encounters with professional plumbers. It meets with on-the-job problems found by plumbers and private persons, especially caused by water quality problems, increasingly aggressive and hard water.

860- Reduced Pressure Zone Assembly is a backflow prevention testable device, designed for high hazard applications to ensure the protection of drinking water supplies from dangerous cross connections.  Available in sizes 15-50mm.

The Febco head office is based in North Andover. Established in 1924, Febco originally manufactured backflow preventers, automatic sprinkler systems and flow control products.  The Febco brand is a worldwide recognised brand.

E – Is it possible for the safety group to open at a pressure of 3 or 4 bars? No, safety groups made to French standards, and the SFR valves in particular, are designed to stringent specifications. By their manufacture, the valve cannot open at a value of only 3 or 4 bars. Each SFR safety group is manufactured, adjusted and checked individually in our BVQI (Bureau Veritas Quality International) ISO9001 certified factory. The valve is set to 7 bars according to the NF standard. The tolerance required by this standard cannot be below 6.65 bars.

825Y- Reduced Pressure Zone assembly this valve is designed to protect against high hazard ratings suitable for chemical plants, hospitals and morgues. The device is Backflow prevention testable, compact in size and designed to work under mains pressure.  The device comes in a range of sizes from 20-50mm.

If you have a pressure reducer and the flow does not slow when you open a hot water tap, the probable cause is the pressure reducer leaking. It needs to be replaced.

C - Every evening, but also during the day at different times, the safety group installed on the hot water tank leaks: Is this normal? The safety group opens and leaks as soon as the pressure reaches 7 bars. There can therefore be two causes: - The supply pressure is over 7 bars, since there is no pressure reducer on the cold water supply, - The pressure reducer is leaking.

WattsBackflow Preventer

B - Every evening at the same time, the safety group installed on the hot water tank leaks, but in greater proportions. Is this normal?

LF880V- Reduced Pressure Zone Assembly is designed for your larger hospitals and chemical plants with a high water usage protecting against high hazard facilities.  The device is fitted with test valves to ensure backflow prevention is maintained.  It features an epoxy coated ductile iron body.  Maximum pressure 175psi.  Available sizes 65-200mm.

If the plumber finds, as he dismantles the valve, that the valve facing has been attacked by corrosion due to poor water quality (cf. E.G. 60.1), it is necessary to change the safety group. You are then strongly advised to install a safety group with a SFR STAINLESS STEEL type.