The mechanical systems, which offer air quality and thermal comfort in an indoor area are internally linked and they are generally grouped together and are known as HVAC systems. These systems comprise of heat pumps, furnaces, boilers, central air conditioners, rooftop units, chillers and packaged units.
A general utility of HVAC Valves is to control flow in pipes. The major parts of HVAC system are cooling water pumps, water chiller, fan coil units and air handling units etc. require valves to control the flow of water, air and gas.
For Ventilation, Heating and Air Conditioning HVAC is the acronym. HVAC relates to different systems which are being utilized together with cooling and heating in commercial as well as residential buildings. It is HVAC system that keeps you cool and fresh in summer and in winter the same makes you feel comfortable and warm. Along with keeping a place warm or cool the HVAC system is also accountable for the betterment of air quality inside the building.
Various Types of Valves Which Are Used in HVAC System:
In HVAC system, commonly used valves are Ball Valves, Plug (Seat) Valves and Butterfly Valves. Apart from these mainly used valves the other valves which are being made use of are Diaphragm Valves, Knife Gate Valves and Gate Valves.
Heating and cooling Hydronic-Triple Duty Valves work as Check Valve, Balancing Valve and Shut-Off Valve all together simultaneously. To check the flow of water in HVAC system, Automatic Flow Limiting Valves are made use of to change the speed pumping systems. Where as to lessen the temperature of water in the domestic hot water pipe Automatic Temperature Control Valves are utilized in HVAC system.
In the HVAC Hydronic Loop, a PRV is used to lessen the pressure of water. While Circuit Setter Valves are used to regulate a fixed volume of flow through a piping loop.
HVAC system regulates the temperature of the indoor space along with maintaining the indoor air quality. But to get the best result from HVAC system, it is a must to opt for the use of the world class quality 4Matic industrial valves.
One of the leading valves manufacturers and suppliers in local as well as international market, 4Matic has a very tough course of action as far as their manufacturing procedure is concerned to keep their customers rest assured for the utmost top quality industrial valves.
Different types of valves and fittings are used for water piping in HVAC industry. Various type of valves have their own manners of operation. Certain valves are inducted for maintenance purpose, while certain are for the reason of water flow control.
Types of Valves:
Balancing Valves :
These valves are made use of in chiller’s evaporator’s outlets for condenser water pipes and also chilled water outlet. There is a scale mark on the valves, so as to alter (change) the flow of water through the pipe by opening or closing the valve. While commissioning the needed flow (USGPM) as per design calculations is modified and fixed for the operation.
Butterfly Valves :
As per the name, the design of this valve just resembles to a butterfly. These valves are inducted in chilled water pipes at the end and the starting points of each unit or pump and all fittings are fixed in between these valves. Mainly these valves are utilized for the maintenance and also to stop the flow of water in case of breakdowns. For balancing purpose also these valves can be used but that is only in case of a very low gpm flow.
NRV or Check Valves :
NRV i.e., Non Return Valves are fixed at discharge outlets of pumps because the water in pipes once passed through these valves cannot flow back. A door of one or two top quality plates is there in these valves. To safeguard the pumps from unexpected effect of water on its pump assembly or blades these valves are effectively useful in chilled water piping system. The pumps’ motors would get damaged if NRV is not used in the system. The manufacturer marks an arrow on the body of the valves which shows the direction of the flow of water.
Ball Valves :
Generally these valves are installed in chilled water line of small sizes. Ball Valves are fixed at the inlet and outlet of every indoor unit e.g., FCU, AHU and also in cooling towers.
Modulating Control Valves :
From the name of the valve itself it is understandable that Modulating Control Valves are there to control the flow of chilled water through the indoor units. Once the desired temperature in the conditioned space is attained then this valve will halt the supply of chilled water and bypass the same to return water pipe. On the top of this valve there is an electric motor which operates these valves and this motor is directly linked to the valve shutter.
Pressure Regulating Valves :
These valves are used to control the water pressure in chilled water pipes at the time of commissioning.
Float Valves :
Very common and very popular are the phrases that are used to refer Float Valves. Only in makeup water pipes to regulate the volume of needed water in cooling towers or water tank, these valves are used. In this valve a floating ball is attached to the lever of the valve, that opens or closes the valve when water level changes. If the water level is low the valve opens and if the water tank is fully filled, the ball pushes the lever and closes the valve.
Y – Strainer :
The most significant fitting that is used in the chilled water line is Y-Strainer. It works like a filter as it removes small particles from water. Y-Strainer is always there in supply line of indoor units and also in suction line of pumps. This valve has an inbuilt filter and functions on the gravity to filter the water. These valves must be installed in a particular manner that the part of the valve which has the perforated sheet, which works as a filter that can be opened and this should be projected downward as shown in the figure below.
Pot Strainer :
The function of Pot Strainer is the same as that of Y-Strainer but the built up of these strainers is far apart. These strainers are installed in the main return pipe bringing all the water that has come back from the building to the pumps and linked to the suction line of pumps header.
Expansion Tanks :
In a chilled water system, Expansion Tank is of utmost importance. What would happen if water in indoor units suck up heat?
If Expansion Tank is not used in chilled water return line, the when the water begins to increase, the pressure will build up in the pipes and it may lead to leakage at different fitting points, valve joints and threads and this pressure may result in to bursting of the pipe. Therefore, to check the increment of water in the chilled water piping system Expansion Tank is a must. To release the water pressure, an Automatic Pressure Relief Valve keeps functioning.
