The water pipes laid in multifamily or owner-occupied dwelling represent the complex system requiring leaving and attention. One of utilization properties of such system – water pressure. Operation of plumbing and heating appliances depends on this indicator.
Reasons of reduction of pressure of water
Insufficient pressure in water supply system – problem which quite often owners of apartments and owner-occupied dwellings should face. The low pressure of water sometimes makes impossible use of shower cabins, dish washers and other household appliances. There are several ways which allow to regulate water pressure in system.
Basic reasons of violation of pressure of water in water supply system:
- accidents on the center water supply system;
- violation of tightness of the pipeline, leakage in all-house system;
- wear and contamination of pipes;
- unauthorized modification of water supply system.
Unauthorized change of system meets when on first floors of multifamily houses arrange saunas or car washes where water supply is calculated without needs of residents, only on the basis of needs of the enterprise.
The most effective way to increase pressure in water supply is to put the additional pump or even the pumping station with capacity of the considerable size. Both options have the advantages and shortcomings.
Norms of pressure of tap water
For assessment of pressure level two basic measurement units – bar and the atmosphere are used. The difference between them is that 1 bar is equal 1.0197 atmospheres. Therefore they can be considered almost identical. One measuring unit corresponds to pressure which makes water column 10.19 meter high.
If the pump needs to pump water to height of the fourth floor (these are about 10 m), then at the entrance to water supply system pressure in 2 atmospheres will be required. If at the same time the submersible pump pumps water from the well of 20 meters in depth, then at the output of the device pressure about 5 atmospheres has to develop.
The leading role when calculating system by means of which there is water supply to the house is played by water supply system resistance. It depends on diameter and length of pipes, on number of turns and material of which the pipeline is made.
Owners of owner-occupied dwellings should know that artesian wells can provide pressure to 10 atmospheres. The majority of the locking and regulating knots under the influence of such pressure collapse, on sites of water supply system there are leakages.
Pressure of cold water in water supply system according to norms has to be in range from 0.3 to 6 atmospheres. Admissible borders of pressure of water are that. Owners of owner-occupied dwellings should count pressure independently. It is considered that pressure higher than 6.5 atmospheres is capable to put sensitive household appliances out of action. Norm for hot-water supply pressure ranging from 0.3 up to 4.5 atmospheres is considered.
Determining normal pressure for owner-occupied country house, it is necessary to remember that some types of plumbing will not work with excessively low pressure. For example, the washing machine demands 2 atmospheres, the fire extinguishing system – 1.5, and jacuzzi – already 4 atmospheres. For the system of watering of lawns the pressure has to be stronger, most often – up to 6 atmospheres.
For country house the standard mark in 4 atmospheres will be optimum level of pressure in water supply. Such pressure quite will be enough for correct work of the vast majority of devices in which water is used. Fitting and knots of the regulating and shutoff valves can quite sustain this pressure.
According to the established norms pressure in water supply system of the centralized type is 4 atmospheres, but in practice it is in range from 2 to 6 atmospheres. If the network is subject to sharp hydraulic jumps, it can have an adverse effect on condition of the sanitary equipment. So-called hydroblows in city networks of water supply happen at sharp hydraulic jumps, for example, at formation of air locks. Plumbing elements, mixers, cranes, washing and dish washers, as a rule, pay off on the working pressure of 6 atmospheres.
For measurement of pressure in the system of supply of water use the manometer. Usually it is established at the entrance to the house, in the same place, where also the water flow counter. Some types of the equipment are already on sale complete with the manometer. The heating boiler can be example. The normal manometer has the scale graduated from 0 to 7 atmospheres (bars) that gives the chance to use the device in the apartment or owner-occupied dwelling.
In general norms of pressure should be considered relative; most often they depend on number of points of water consumption. The more such points, the pressure in system in case of simultaneous opening of all cranes and introduction to operation of all devices consuming water will be lower. Therefore try to calculate pressure in water supply system with some stock that at the maximum intake of water the pump could guarantee sufficient pressure in each point.
Choosing household appliances, it is always necessary to specify according to technical documentation what minimum and maximum parameters of pressure, within which the equipment can smoothly work. It is desirable that possibilities of the equipment had necessary stock on the level of allowable pressure in system.
How to increase pressure in water feed system
For water pressure increment in house systems use:
- manually controlled pumps;
- automatically operated pumps of elevated pressure;
- pumping stations.
Use of the pumping station which the additional tank having big capacity joins is considered the most practical way. Such decision gives the chance to eliminate hydraulic jumps. Installation of holding tank allows to have the sufficient water supply necessary for domestic needs.
Pump of elevated pressure
The pump of elevated pressure can have not the really big power as it increases pressure just before points in which the water intake is carried out. Power of some models of pumps can be regulated in the manual mode or automatically. The second option is more practical: power supply of the pump joins itself if pressure falls below the limit set by the user. It is necessary to consider that the pump will be able to lift pressure only if she moves from city water supply system. It is possible to increase pressure in such a way by 1.5-2 atmospheres.
Preference should be given to vibration pumps. Models of centrifugal type are capable to create harmful discharge, that is to pump the water saturated with air. It is necessary to put the pump on the pipe conducting to the household appliance in which water pressure is required to be increased. For simplification of mounting of the pump quite often use rubber or polypropylene hose which usually go complete with this equipment.
Pumping station
Having number of advantages, the pumping station with capacity has essential shortcoming: for its device it will be required to allocate considerable space in premises, on the attic or in the basement of the house. One more minus of such decision: automatic switch-on of the station is followed by the high noise level that is not observed when using the compact pump.
Besides, the container with water (hydroaccumulator) demands regular service, cleaning and disinfection. Water in the tank should not stand more than three days. Advantage of use of such system is that it is possible to fill capacity at night; when using the counter with two tariffs it gives the chance to considerably save the electric power.
It makes sense to put the accumulative pumping station if water in the house does not rise to the most upper floors, and pressure in system does not exceed 0.2 atmospheres. Mounting of the station is carried out in point where external and internal branches of the pipeline connect. Principle of work of the accumulative station following. In the beginning the pump pumps water in the hydroaccumulator; liquid arrives there until in tank pressure 1.5-2 atmospheres is not established. After that the pumping station is automatically switched-off. If pressure has fallen below control mark, the pump is started.
Pumping stations give the chance:
- to establish desirable pressure in the house;
- to use sanitary devices which demand rather high-pressure water;
- to provide uninterrupted water supply even if it is absent in the center water supply system.
The pumping station with holding tank has several enough difficult knots therefore will be able to carry out its mounting by own efforts not everyone. That the equipment worked trouble-free, it is recommended to entrust its installation to professionals.