Any piping arrangement requires different types of valves to control the fluid flow within that system.
The valves can be functioned manually or have an actuator to control the valve opening; the actuator can be pneumatic, hydraulically, or electrically operated.
For the process of piping, the engineer must be aware of all kinds of valves, detailed information related to the operation, maintenance, adjustment of the valve is crucial to achieving success and its total activity will depend on it.
Objective of various types of valves:
- To control the water flow rate.
- To prevent leakage.
- To accept or release air into the pipeline.
- To create an effective delivery system.
Different types of valves:
Ball Valves are quarter-turn valves, commonly used for bi-directional isolation applications.
Since the ball moves across the seats in a wiping motion, the ball valve is an excellent and cheapest shut off device for DN50 and lesser CHW pipelines to blockages due to debris in the medium.
When the ball valve is fully opened, it has no obstruction in the flow path causing slight friction loss.
Ball valves could be installed in any direction on the pipe.
Gate Valves types:
The gate valve is activated by a negotiated stem that connects the gate to the actuator, i.e., handwheel or motor.
They are depicted as either a sprouted or a non-sprouted stem, at base the end of the stem is threaded.
The rising stems are fixed to the gate; it is raised and lower as the valve operates, giving a visual indication of the valve situation.
These valves are manufactured in wafer and lugged types, it may be lever or gear operated.
The valves are available with cast or ductile iron body and internally EPDM-lines seat providing a resilient bubble tight shut off for total isolation.
The discs are available in highly robust materials- nickel plate ductile iron or stainless steel.
Butterfly valves could be installed in any direction on the pipe except the position with a negative angle concerning the top side of the valve to avoid condensation on the gearbox.
Check valves operates automatically to allow fluid to flow in only one direction.
The valves serve the pump protection from the reverse flow and water hammer.
Check valves may also be required in lines feeding the secondary CHW system, in which the pressure can rise above the primary system.
Swing check valves could be installed on the pipe in the horizontal and vertical (upstream) directions.
The wafer design enables easy installation, it has lesser weight, lesser space requirement, and easy maintenance compared to flange models.
Air valves types:
It is provided at the exit; the air gets deposited in the pipe.
These valves are also located near and above the hydraulic shield; the chamber is filled with water which has been drawn from the pipeline.
This makes the float to touch the roof of the chamber, closing the poppet valve.
As air enters the water pipe, the chamber and accumulates under the roof of the chamber.
Due to air pressure, the float is pulled down and the poppet valve is open to allow air to escape.
As air moves out of the chamber, the water level in the chamber rises, causing the float to stop working so that the poppet valve is closed.
This action is repeated whenever air accumulates in the pipe.
These valves are also called check or non-return valves; water moves only one direction is an automatic device.
When there is a regular flow in water, the value rotates around the axis to maintain the flow of water.
When the water flow is reduced or stopped, this valve is set to prevent the backflow of water, hence it is also called a non-returning valve.
It is placed in a pipe that receives water directly from the pump.
When the pumps stop providing water to the pipe; due to this valve, the remaining water in the pipeline is not allowed to return to the pump, it is protected from any such damage.
They are handy at the point where polluted water systems and potable water systems are interlinked.
Due to this valve, the contaminated water is completely prevented from entering the potable water pipe.
Relief Valves Types:
These valves are also called automatic cut-off valves or safely valves or pressure valves.
When the water pressure exceeds the predetermined limit, the valve is driven and the water pressure automatically decreases.
The spring used in this value is adjusted for the maximum load, so when the load goes above this limit, the amount helps reduce the burden thus the water pressure in the pipe.
These valves are located at all points where there is a risk of increased pressure.
When the water pressure exceeds the maximum limit, the pipe can withstand the valve and come into action and the pressure immediately decreases.
They are located dead-end in the main and used to remove solid materials, such as sand or silt from the water.
They are hand-operated valves provides clean and clear water flows through pipes.
Sluice valveS types:
It is also called a gate valve or shut-off valve, it controls the flow of water; they help in dividing the water level into the required sections.
These hand-operated valves have a handle by raising or lowering them; the valves are either lifted or pulled down to control the flow of water.
It is mainly used for the management of the intermittent system of water supply at all junctions.
These valves are used to divide the water supply from the main areas and also control the amount of water for all subclasses.
Flexible joints connectors are widely used in piping and pumping applications in the suction and delivery pumping lines for air-conditioning, ventilation system, and chilled water installation.
Rubber or elastomer flexible connectors are efficient & economical ways to provide accommodations pressure loads, relieve movement stress, reduce noise, isolate vibration, reimburse for misalignment, and lengthen the life of drive equipment.
Special built-in features will also eradicate electrolysis, counter expansion, and contraction against start-up swell forces.
Flexible expansion joints are used widely in the building services industry and other general industrial uses.
It is designed to accommodate vibration and thermal expansion to reduce transmission of noise on a wide range of systems.
These include steam, condense, hot water, heating and air conditioning systems.
Other applications include power generation plants, offshore (gas and oil rigs) and problems.
The strainer is used in a piping system as a mode of filtration, thereby protecting critical equipment components from contamination that may be carried by the medium.
All dimensions of filters have a stainless steel perforated screens with a blow down function.
The filter could be installed in the pipe in the horizontal and vertical directions.
The need for valves is used to offer better water management.
The types of valves are ball valves, gate and butterfly valves, diaphragm and globe valves which can be used to manage better and to distribute piped water in a better way.
These valves are used in different places according to the need of water supply and size of pipes.