Autonomous water supply systems have many advantages due to independence from the central water supply line. But they also have disadvantages, one of which is the risk of water hammer. With a sharp opening of the valve in the circuit, the pressure rises, which can adversely affect the condition of the pipeline and pumping equipment. The hydraulic tank for water, which performs the function of a buffer fluid content, can insure communications from such phenomena.
Tank device
A hydraulic tank is a tank whose design is designed for temporary water content. Welding steel is usually used as the material for the case. To protect the surface, manufacturers use different coatings, the most common of which is reflow powder paint. The design is usually complemented by welded posts and counter flange. The galvanized flange provided by the union is used for connection. The number of communication outputs may vary depending on the tank model. Without fail, the device of the hydraulic tank for water includes a membrane. It is usually made from butyl rubber and can be replaced during operation. This is a common device, but its execution may be different - in particular, the design of the model is divided into vertical and horizontal.
Types of structures
In conditions of small space, it is recommended to use vertical models of the hydraulic tank, which take up little space, but also differ in small volume. The features of such equipment include the presence of a booklet on the case, which allows you to release excess air. In the choice of vertical hydraulic tanks, it is initially worth calculating the possibility of connecting a submersible pump - as a rule, both units are selected together taking into account the correspondence of their operating parameters. The topic of pump selection is crucial for this type of equipment. It is important to remember here, why do we need a hydraulic tank for water in principle? It performs a protective function in relation to the pumping equipment and the associated pipeline. And if a surface pump is used, then the choice should be made in favor of a horizontal hydraulic tank. This decision is due to the fact that tanks of this type support the possibility of overhead mounting. That is, the pump is located on the hydraulic tank. But it is important to consider that such a design will take up more space, but the volume of the damping capacity will also be higher. To release excess air from the tank in this case, a separate pipeline circuit is provided. Technically, this function is realized by the outlet nipple and the drain channel with a ball valve.
The principle of operation of the equipment
Having dealt with the constructive device of the hydraulic tank, you can proceed to the study of its operating principle. To begin with, the standard autonomous water supply system operates under pressure from 1 to 3 atm. Extreme levels of this indicator as such do not harm the equipment and piping pumping water, but a sharp drop can provoke a water hammer. And even if the system can withstand it in some cases, then regular pressure loads will adversely affect the pump resource. What is the principle of operation of a hydraulic tank for water expressed in terms of protection against sudden changes in pressure? The presence of such an addition in the circuit of the water supply system will allow in case of potential pressure increase to transfer the load to the tank. The water contained in the tank will be used primarily with optimal pressure maintenance. When the supply is exhausted, the main resource of the pipeline will be connected, but also under conditions of acceptable pressure indicators.
Unit Specifications
In choosing a hydraulic tank, two main indicators should be taken into account - working pressure and volume. As for pressure, experts recommend using units that maintain a value of 0.1-0.5 bar less compared to the optimal pump load when turned on. If the acceptable pressure for a particular pump is 1.7 bar, then the tank should be selected with a value of 1.4-1.6 bar. The volume of the tank also varies. The standard for home systems of autonomous water supply is considered to be 80-100 liters. If you plan to serve more than 5 consumption points, you will need a 300 liter hydraulic tank for drinking water, providing the function of pumping units with a capacity of more than 2 kW. By the way, for the water supply of one consumer, it is possible to limit the capacity to 25 liters, which can be interfaced with pumps, the power potential of which is up to 0.5 kW.
Cargo tank
The beginning of the development of the concept of this equipment was laid by the invention of cargo tanks. They have a simple device and operate on the principle of consumption of potential energy of the cargo. During operation, the tank provides pressure on the water, which allows you to create the optimal load balance in the circuit. The advantages of such hydraulic tanks for water include high capacity, low maintenance and an affordable price tag. But also cargo tanks have significant disadvantages, which are reflected in low rates of maintained pressure, large sizes and risks of leakage. In addition, such equipment has limitations on the ability to connect to pumping equipment - this applies primarily to energy intensity. The pump in the water supply system must be low-power, otherwise the hydraulic tank will not cope with the function of equalizing the pressure drops.
Spring hydraulic tanks
In this case, the process of normalizing the pressure in the water supply system is provided by mechanical energy. It is formed by compression of the spring mechanism, which allows you to generate sufficient force for the accumulation of water and its return to the circuit with sudden pressure drops. Unlike cargo tanks, such a tank has a high energy intensity, so it can be used in systems with powerful pumps. However, the sanitary fittings of such devices limit their use due to the risk of damage under the influence of aggressive environments. This is the optimal hydraulic tank for cold water, but high temperatures negatively affect piston seals. There are also risks of breakdowns and deformations of the spring group.
Pneumohydraulic hydraulic tanks
Tanks of this type are widely used both in enterprises and in the domestic sphere. Energy for controlling pressure is generated by compressed gas. This principle of creating hydraulic forces determines the design features of the unit. It has a floating piston with a flexible membrane and a float mechanism for monitoring the operating parameters of the medium. Stimulation of the optimal liquid level in the tank is provided by a membrane that stretches or contracts depending on the current pressure level in the water supply line. Materials for the construction of the structure make it possible to use this hydraulic tank for hot water without the risk of premature breakdowns. Manufacturers count the elemental base for operation with increased pressure indicators with a large number of operating cycles.
Installation of a hydraulic tank
It is desirable to install the unit in a heated room on a stable surface and near pumping equipment. Fixing can be provided with complete fittings in the form of fasteners or due to frame profiles - for example, if we are talking about installation on the basis of the pump itself. Before connecting the water tank to the supply circuit, flush the system. To do this, water is supplied to the channel with a small pressure load for 5-10 minutes. This session must be repeated 2-3 more times, after which the system is introduced into the water supply infrastructure. The first start-up of the device can be carried out under a pressure of not more than 2 atm. During operation, it is important to prevent the risks of clogging of the tank, its physical damage and overvoltage as a result of the mismatch of the operating parameters with the pump characteristics.
Control systems
Most modern hydraulic tanks are controlled by automatic means of monitoring operating parameters. The simplest devices provide for the regulation of equipment due to 2-3 commands supplied to the valves through the relay. Sophisticated high-tech control systems make it possible to take into account several parameters, making decisions on the optimal and more precise regulation of the volume of fluid output at times of pressure drops. Such systems, in particular, are the automation of the Gileks hydraulic tank. Adjustment of water pressure in this equipment is carried out by a control relay that accepts readings from two pressure gauges. One of them is located in the upper part of the tank and allows you to take into account the pressure for optimal release of excess air. And the second is located in the area between the pump and the unit for supplying water to the tank. This is the most important regulation zone with which the pressure switch and the main control unit interact directly.
Finally
A typical configuration of a water supply device with a submersible or surface pump does not at all require the mandatory use of a hydraulic tank. Initially, such systems are designed with the possibility of using pumps without additional equipment. But when it comes to infrastructure with high productivity, the water tank will provide the necessary protection in case of unforeseen overload. And even if you do not take into account the risks of serious damage to communications, an auxiliary means of regulating pressure will help reduce wear on the units. In addition, the hydraulic tank can also act as a backup means of providing water. But this applies to tanks with large capacity, which are rarely used in domestic water supply systems.