Pumpac

1.       How do I know what pressure and/or flow I require?  Pressure is determined by the height you need to pump, the size and length of the pipe work through which you are pumping the associated friction losses and the residual pressure you require at the out let (valve, tap etc). The flow is determined by the number of showers, taps toilets baths and appliances you may have. There are standard formulas to work these requirements out and our design team can help you work out your requirements at no cost.

2.      What is an inverter driven or variable frequency drive pump? A variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variable-frequency drive includes a rectifier so that DC power for the inverter can be provided from mains AC power. Since an inverter is the key component, variable-frequency drives are sometimes called inverter drives or just inverters.

 

3.      Why use an inverter driven pump? In recent years, as the price of VFD,s ( inverter drives)  has come down many pump manufacturers and suppliers have started to use inverter driven pumps as a means of reducing energy costs, and to incorporate a more 'green' ethos into their plant equipment policy.

Inverters work by regulating the speed of a pump, such that a larger pump may operate at reduced speed to meet lower demands, and as demand increases the pump will ramp up to meet that design demand, thus reducing energy costs. This means that a fixed speed pump no longer needs to run at 100% in order to meet a small demand .

The system works due to the ratios of
Speed : Duty : Energy Consumption; it is known that if the speed is reduced by half, the duty will reduce to one quarter, but the energy consumption will be only one eighth. Pump wear is also significantly reduced.

The initial investment can be higher than for a fixed speed pump but depending on the size of the system there are both economic, environmental and operational benefits to inverter driven pumps

 

4.       Why is mains pressure so poor and what can I do to improve it?  Water Utility companies have to meet pre set OFWAT targets to reduce leakage within their water supply networks and one method of achieving this is by reducing water pressure. Many areas within the UK are guaranteed only 0.7 to 1 bar at the road side. These  factors mean that the need for boosted supply is no longer restricted to high-rise buildings and is often essential even for houses where modern water systems require good pressure – typically at least 2.0 bar and preferably 3.0 bar for the best performance.

 

5.       Can I put a pump on the incoming mains supply?  Water regulations do not allow pumps to be connected directly  to mains supplies as there is always the risk of contaminated water from the downstream side of the pump to back siphon into the public main. A break tank must be installed with an air gap to prevent back siphoning. The most common method is to use a tank and ball float valve to supply it.

 

6.       How big a tank do I need for water storage? Water storage capacity is determined by the estimated flow requirement within the building and the speed of the replenished flow into the tank. To work this out we use an equation and detail on the number of showers, baths , toilets etc within the building and any information we can get on the incoming supply, size distance from road etc. Using this information we can then supply you with a required storage capacity.

 

7.       Why do I need more than 1 pump? It is common practice to run a water supply and waste water system on more than one pump. There are a number of reasons for this. Duty/Standby systems have an extra pump to take over the duty should the duty pump fail. Duty/assist systems have more than one pump, and the assist pumps help meet the total duty required. Should one pump fail there will still be water available but it may not meet the full demand. It is common to use Duty/standby systems where the consequences of a failed pump would be very serious, school, hospital, large block of flats etc

 

8.       What is the advantage of a Grinder/Macerator pump ? A Grinder/Macerator pump grinds and cuts solids toilet waste into small particles using a cutter mechanism for easier discharge. There may be a number of situations where this is an advantage, the discharge main is an existing smaller bore pipe. There is a requirement to pump to a high head. Macerators will generally cope with higher heads or where effluent is being stored before emptying, in a boat or bus etc where space is at a premium. The downside to macerator pumps is that they require more servicing with blade mechanism changing and are likely to require more power to operate them.