Description

CEM – Accumulator Tanks

An accumulator tank is an important part of any pressurised water system that includes a pressure-controlled or jet pump. Some modern computer-controlled pumps may not require an accumulator tank. Fitted close to the discharge port of the pressurised water pump, the accumulator tank acts as a pressure buffer, ensuring a smooth flow of water from the outlets. Without an accumulator tank, the pump is liable to switch itself rapidly on and off whenever its flow rate exceeds demand from the outlets. Constant on-off cycling leads to increased pump wear and unnecessary battery drain. The accumulator tank stops this rapid cycling, resulting in smooth water flow (important in showers) and extended pump life

An accumulator tank is much the same as an expansion tank however the pressure of the membrane should be set at a level just below the maximum pressure of the pump. The main sifference is that the tank stores the water pressure to avoid the pump system cycling (switching on and off frequently). An accumulator can also be used before the pump system to act as a buffer tank (sometimes referred to as a header tank)

Our range of accumulator tanks are supplied in either polished stainless steel and white painted steel, however, we can paint them in any colour that you require, just get in touch with us

FAQ’s

Why do I need an accumulator tank?

An accumulator tank is an important part of any pressurised water system that includes a pressure-controlled pump. (Some modern computer-controlled pumps may not require an accumulator tank, but see Section B – Expansion tanks.) Fitted close to the discharge port of the pressurised water pump, the accumulator tank acts as a pressure buffer, ensuring a smooth flow of water from the outlets. Without an accumulator tank, the pump is liable to switch itself rapidly on and off whenever its flow rate exceeds demand from the outlets. Constant on-off cycling leads to increased pump wear and unnecessary battery drain. The accumulator tank stops this rapid cycling, resulting in smooth water flow (important in showers) and an extended pump life.

Where do I fit an accumulator tank?

The accumulator tank should be fitted in the discharge line from the pump, as close as possible to the pump itself. The tank will serve only as a buffer tank if fitted in the pump inlet pipework

How do I install an accumulator tank?

The tank should be installed in a dry place. Tanks may be fitted in any attitude, vertical or horizontal. The tank may be secured by stout strapping or by stainless steel bands, or it may be mounted in a wooden cradle. The steel tank casing is robust, but care should be taken during installation not to scratch, dent or puncture it

What size of accumulator tank do I need?

This depends on the number of outlets in your system, their frequency of use, on the flow rate of the pump and on the space available. The larger the tank, the less frequently the pump will start, and the longer it will run before stopping

At what pressure should I set the accumulator tank?

The pressure in the tank is adjusted by means of the air valve in the closed end. The tank is supplied with an internal pressure of about 2.8 bar (35 psi). Reduce this pressure to 2 – 3 psi below the cut-in pressure of the pump (refer to pump instructions for details). This pressure adjustment is best done before the installation of the tank, using a car-type pressure gauge to determine when the required pressure is reached, as follows:

1. Depress the central pin of the Schrader valve with your finger, to release gas
2. Release gas a little at a time, until the pressure is correct
3. If you release too much gas by mistake, air may be pumped back in with a hand – or foot-pump

If the tank pressure requires adjustment after installation, ensure first that the pump is switched off and that an outlet is open so that there is no pressure in the system. Then regulate the pressure as indicated above
Check the accumulator tank performance in this way every 6 months, and adjust the pressure if necessary

Winter precautions

To avoid the risk of frost damage, drain all the water from your pressurised water system, before winter lay-up. Switch off the pump, open all outlets until the flow ceases. This will allow water to be expelled from the accumulator tank. Drain all remaining water from the lowest point in the system. Remember to drain your calorifier from the bottom (cold-water inlet)

CEM Pumps and blowers page for accumulators

Thread: BSP (EN 10226-1 – ex ISO 7/1)

About CEM Pumps and Blowers

Established in 1970 C.E.M. elettromeccanica S.r.l. has been a leading manufacturer of electric pumps and DC motors primarily focussed for use in the maritime sector
In the 48 years, we have been making motors and our constant expansion in the national and the international markets have resulted in the broadening of our extensive product range

…highest quality materials…design…innovative production processes…remarkable lifespan…

This makes us the ideal partner for large and medium-sized boat builders of pleasure, fishing and military vessels.

Our extensive range now includes:

• DC and AC electric pumps
• Belt driven pumps, with manual or electromagnetic clutch
• hydraulically driven pumps
• water pressure systems
• centrifugal and axial blowers
• diesel driven pumps
• manual pumps
• DC motors

Our commitment to using the highest quality materials used, the special care invested in the design and in the innovative production processes we adopt, we are able to offer excellent performances and a remarkable lifespan of our products exactly what you need when our product can offer extra hours of safety when in difficulty

The CEM factory is based in Nonantola close to Modena in Italy, and is a family-owned business with generations of experience in the manufacture of pumps, blowers and electric motors

All of our products are built to standards that are in accordance with classification and certification can be obtained from each of the bodies: Bureau Veritas, Det Norske Veritas (DNV), Lloyd’s Register and RINA