Every 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, while the actuator can be pneumatic, hydraulically, or electrically operated.
For the process of piping, the engineer must be aware of all kinds of valves with detailed information related to the operation, maintenance, while adjustment of the valve is crucial to achieving success and total activity will depend on it.
Objective of valves:
- To control the water flow rate.
- Also, 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 because the ball moves across the seats in a wiping motion.
This valve is an excellent and cheapest shut-off device for DN50, while 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.
These valves could be installed in any direction on the pipe.
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 the base 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.
Butterfly valves are manufactured in wafer and lugged, it may be lever or gear operated.
These 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, i.e. nickel plate ductile iron or stainless steel.
These 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 which serve the pump protection from the reverse flow and water hammer.
These 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 as it has lesser weight, lesser space requirement, and easy maintenance compared to flange models.
Air valves is provided at the exit, the air gets deposited in the pipe.
These types of valves are also located near and above the hydraulic shield, the chamber is filled with water that has been drawn from the pipeline.
This makes the float touch the roof of the chamber, closing the poppet valve as air enters the water pipe, the chamber 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.
Reflux valves are also called check or non-return valves in which 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 and 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.
7.Relief Valves Types:
Relief 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 of 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 which comes into action and the pressure immediately decreases.
Scour valves are located at dead-end in the main which 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.
9.Sluice valveS types:
Sluice valves are also called a gate valve or shut-off valve, it controls the flow of water and 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 to control the amount of water for all subclasses.
Flexible valve connectors are widely used in the suction and delivery pumping lines for air-conditioning, ventilation systems, 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 types of valves used widely in the building services industry and other general industrial uses.
It is designed to accommodate vibration and thermal expansion to reduce the transmission of noise on a wide range of systems.
These include steam, condense, hot water, heating, air conditioning systems, and 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.
Also read: Types of Pumps, Types of Dams & Types of Pipes
There are various types of valves that are used to offer better water management, i.e. ball valves, gate and butterfly valves, diaphragm, and globe valves which can be used to manage and 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.