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Valves, Pressure requirements and Safety


Plumbing Fixtures: Chapter 2


Valves


In this module, we will learn about the valves used in residential plumbing. Skip to quiz!


Define Valve


A valve is defined as a mechanical device that controls the flow and pressure in a system. In other words, it controls the flow and pressure of water in a plumbing system. Plumbing valves are devices that control or direct fluid flow by opening, closing, or partial obstruction.


The types of water valves used in the

plumbing system are:

  • Gate valve,

  • Globe valve,

  • Check valve,

  • Ball valve,

  • Butterfly valve, and

  • Pressure relief valve.


Gate Valve

Gate valve is a linear motion valve that is used to start or stop the flow of water. Gate valves are kept in either fully open or closed positions. Gate valves are most commonly used in any process plant or residential purposes.


A gate valve consists of a valve body, seat and disc, gland, and a wheel for operating the valve. The seat and the gate together perform the function of shutting off the flow of water. Gate valves are used for all types of fluids, including water and gas.


Globe Valve


The globe valve is also a linear motion plumbing valve used to


  • Stop

  • Initiate, and

  • Control flow.


During the opening and closing of the valve, the disc moves perpendicular to the seat. The globe valve is used to regulate the water pressure.


The globe valve is also used for complete shut-off of flow. The globe valve has considerably higher pressure loss than a gate or ball valve in the fully open position. The pressure losses are due to the flow of water changes direction as it goes through the valve.


The list of some applications of globe valves:

  • Cooling water systems where flow needs to be regulated,

  • Fuel oil system,

  • High-point vents and low-point drain, and

  • Feedwater, chemical feed, and extraction drain systems.


Check Valve


The plumbing valve used to prevent backflow in a piping system is called check valve. Check valve is also called as a non-returning valve or NRV. The pressure of the water passing through a pipeline opens the valve, while any reversal of the flow will close the valve.

Check valves are unidirectional valves that provide continuous flow in one direction till the pressure remains constant.

The three main types of check valves used are:

  • Ball,

  • Piston, and

  • Stop valve.


Ball Valve


A ball valve is a rotary motion valve that uses a ball-shaped disc to stop water flow. It resembles a plug valve in many ways, when the ball is in a port line, it allows flowing the flow of water. When rotating the valve is 90 degrees, the solid part of the ball stops the flow.


The types of ball valves used in piping are:


  • Floating,

  • Trunnion Mounted, and

  • 3 Way.


The floating ball valve holds the ball in position by compressing two elastomeric seats against the ball. The shaft allows a certain amount of lateral movement of the ball from the pressure acting upward on the ball.


Butterfly Valve

The butterfly valve is a rotary motion valve used to stop, regulate, and initiate water flow. The butterfly valve is designed as a small circular body. These valves are suitable for large valve applications because of their compact, lightweight design.


Pressure Relief Valve


A pressure relief valve is used to protect the equipment or piping system in a sudden increase of pressure or vacuum pressure. This valve releases the pressure or vacuum at a predetermined set pressure.

Recall using valves for controlling the flow of gas through a torch in welding. A pressure regulating valve is used to supply gas at the required pressure from storage cylinders in welding.


A valve is defined as a mechanical device that controls the flow and pressure in a system of water or any other fluid. Valves are of many types, but some of them are used in residential. Each valve has its own features, some of them are used to control, regulate, and allow the flow in only one direction.

The types of valves are:

  • Gate valve

  • Globe valve

  • Check valve

  • Ball valve

  • Butterfly valve

  • Pressure relief valve

Generally, valves are used to control the water flow and provide required pressure at the fixtures.


 

Pressure Requirements and Safety


In this module, we will learn about the pressure requirements and safety in plumbing. Skip to quiz!


Importance of Water Pressure


The water pressure is the force of water flowing through the pipes. Water pressure is measured in bars. Each bar is the force needed to raise water to a height of 10 meters. Each tap or shower will be rated with a minimum required pressure rating, typically between 0.1 and 3 bar.


Low pressure may reduce the flow of water through a fixture. Low water pressure also impacts the flow of water through a shower. Low water pressure also affects when two fixtures are turned on at a time.


The minimum water pressure required for each fixture can be seen in the table.


A pressure regulator is a control valve that reduces the input pressure in the plumbing system to a safe level that will not damage pipes. Most homes have them, but a failing pressure regulator can cause a severe upward spike in water pressure for those who do. It can also have the opposite effect, a sudden reduction in water pressure.


Safety Precaution


Safety precautions are defined as the actions are taken in advance to protect against harmful danger, incident, or failure of any equipment. While installing or repairing plumbers fixtures, necessary safety equipments are:

  1. Safety helmet,

  2. Safety glasses,

  3. Safety gloves, and

  4. Safety boots,

Some of the safety requirements while doing any plumbing work are:

  • Head protection,

  • Respiratory protection,

  • Eye protection,

  • Hearing protection,

  • Hand and arm protection,

  • Foot and leg protection.

Not following safety might lead to hazards.


Some of the hazards are:

  • Respiratory issues,

  • Falling from heights,

  • Exposure to dangerous chemicals or materials,

  • Slips and trips,

  • Hearing loss,

  • Injuries to eyes, and

  • Injuries caused by hand tools.

Working at heights: The danger is great because of the risk of getting into accidents like slipping and falling. Exposure to dangerous materials: Some of the dangerous chemicals they can encounter while working are asbestos and lead, resulting in respiratory problems.


Hazards


Injuries to eyes: Working in places with chemicals and bacteria is usually found in plumbing lines. Direct exposure to chemicals while cleaning the lines and installing a new one can directly affect eyesight.


Injuries caused by hand tools: Plumbers need to use various tools for fixing and repairing works. Injuries caused by hand tools include cuts, fractures, and broken bones. The chances of acquiring these injuries are even higher when the tools are defective, so check them before using them.


Slips and trips: When they are working with bare floors and water, there is also the risk of slipping and falling, leading to injuries. It is also dangerous to work with water if any open-wire contact leads to major injuries or shock. Let us look at the international standards for plumbing.


The International Plumbing Code (IPC) is a proven, comprehensive model plumbing code that works seamlessly with the International Code Council (ICC) family of building codes. It sets minimum regulations for plumbing systems and components to protect the life, health, and safety of building occupants and the public.


The IPC sets minimum regulations for plumbing systems covering topics such as:

  • Backflow prevention

  • Fixtures & fittings

  • Water supply and distribution piping

  • Water heaters

  • Sanitary drainage and venting

  • Traps, grease interceptors & separators

  • Non Potable water systems (rainwater, gray water)


The water pressure is required to ensure the proper water flow from all the fixtures used in plumbing. Safety precautions are to be taken before installing or repairing plumbing fixtures. International standards for plumbing systems need to be followed as per standard codes set by IPC.

 

Question #1: The types of water valves used in the plumbing system are: (Select all that apply)

  1. Ball valve

  2. Tap valve

  3. Gate valve

  4. Pipe valve

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Answer: Ball valve and Gate valve

The types of water valves used in the plumbing system are:

  • Gate valve

  • Globe valve

  • Check valve

  • Ball valve

  • Butterfly valve

  • Pressure relief valve.


Question #2: A linear motion valve that is used to start or stop the flow of water is called

  1. Pressure valve

  2. Gate valve

  3. Open valve

  4. Water valve

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Answer: Gate valve

Gate valve is a linear motion valve that is used to start or stop the flow of water.


Question #3: The globe valve is used to _____ the water pressure.

  1. Divert

  2. Open

  3. Regulate

  4. Close

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Answer: Regulate

The globe valve is used to regulate the water pressure.



Question #4: Which type of valve used to prevent backflow in a piping system?

  1. Faucet valve

  2. Gate valve

  3. Steel valve

  4. Check valve

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Answer: Check valve

The plumbing valve used to prevent backflow in a piping system is called as a check valve.


Question #5: Which is a rotary motion valve that uses a ball-shaped disc to stop the water flow?

  1. Ball valve

  2. Gate valve

  3. Steel valve

  4. Check valve

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Answer: Ball valve

A ball valve is a rotary motion valve that uses a ball-shaped disc to stop the water flow.


Question #6: A valve used to protect the equipment or piping system in a sudden increase of pressure or vacuum pressure is called

  1. Pressure relief valve

  2. Check valve

  3. Open valve

  4. Globe valve

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Answer: Pressure relief valve

A pressure relief valve is used to protect the equipment or piping system in a sudden increase of pressure or vacuum pressure.


Question #7: Water pressure is measured in ____

  1. Inches

  2. Meters

  3. Bars

  4. Miles

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Answer: Bars

Water pressure is measured in bars.


Question #8: Low pressure may _____the flow of water through a fixture.

  1. Neglect

  2. Faucet

  3. Stop

  4. Reduce

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Answer: Reduce

Low pressure may reduce the flow of water through a fixture.

Low water pressure also impacts the flow of water through a shower.


Question #9: Some of the hazards in plumbing are: (Select all that apply)

  1. Falling from heights

  2. Blockage of pipes

  3. Breaking of items

  4. Injuries to eyes

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Answer: Falling from heights and Injuries to eyes

Some of the hazards in plumbing are:

  • Respiratory issues,

  • Falling from heights,

  • Exposure to dangerous chemicals or materials,

  • Slips and trips,

  • Hearing loss,

  • Injuries to eyes, and

  • Injuries caused by hand tools.


Question #10: _______ is a proven, comprehensive model plumbing code that works seamlessly with the International Code Council (ICC) family of building codes.

  1. FDA

  2. Code for work

  3. International Plumbing Code

  4. Residential standards

Scroll down for the answer...
















Answer: International Plumbing Code

The International Plumbing Code (IPC) is a proven, comprehensive model plumbing code that works seamlessly with the International Code Council (ICC) family of building codes.


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