Plumbing Valves

BS Environmental and Sanitary Engineering

Plumbing Valves: Service Pipe – The pipe extending from the main to the consumer’s meter or curb stop i f no meter. Gooseneck - is used to make a flexible connection c onnection between the service and the cock. Water meter – is a device used to measure the volume that passes through the water service. Common Types of Meters: Nutating or Wabbling Disk – is the most common type of meter, meter , the disk is of hard rubber and oscillates in guides, each oscillation indicating a filling and emptying of the disk chamber. Oscillating Piston meter- consists meter- consists of split cylindrical piston which oscillates in a cylindrical piston which oscillates in a cylindrical measuring chamber, permitting water to enter and leave by inlet and outlet ports in the process. Turbine Meters – measure the velocity of water passing, measurement being made by the speed imparted to a turbine wheel. Compound meter – includes a meter of large capacity placed in the main service line to register large flows and a small bypass meter to measure small f lows, together with automatic valves for diverting the small flows to the bypass. Valve – is a fitting installed by plumbers p lumbers on a piping system to control the flow of f luid within that system in one or more of the following ways. 1. To turn the flow on 2. To turn the flow off

Types of Plumbing Valves: -

Gate Valves or Full Way Valve –They are used when repairs are needed in a distribution system, it is necessary that the valve shall be shutoff. They are valves that control the flow of liquid moving through the valve of a gate -like wedge disc with fits against a smooth machined surface, called seat, within the valve body. A valve in which the flow of water is cut off by means of a circular disc fitted against m achine-smoothed faces, at right angles to

the direction of flow. The disk is raised or lowered by means of a threaded stem connected Plumbing Valves

Prepared by: Engr. Ruel Galutan


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to the handle of the valve. The opening in the valve is usually as large as the full bore of the pipe. A valve iin which the flow of water is cut off by means of a circular disc fitted against machinesmoothed faces at right angles to the direction of flow.

Two parts of a Typical Valve: 1. Solid-wedge Disc - The solid wedge is the oldest form of gate valve and a drawback to this design is that it does not have any flexibility. There is the chance of solid disc getting jammed in the seats if there is any valve body/seat distortion due to extreme temperature fluctuations.

2. Split-Wedge Disc - This is of a two-piece design having mating surfaces on the back side of each disc half. This allows the downward stem thrust to be uniformly transferred to the disc faces and onto the seats. This provides protection against jamming due to thermal expansion.

Three Types of Stems: 1. Rising Stem-Outside Screw and Yoke (OS & Y) 2. Rising Stem-inside Screw 3. Non-rising Stem-inside Screw

Rising Stem-inside

Plumbing Valves

Non-rising Stem-inside



2. Globe Valve – a compression type valve in which the flow of water is controlled by means o a circular disc that is (compressed) onto or withdrawn from an annular ring known as valve seat, which surrounds the opening through which water flows. - A valve in which the flow of fluid is cut off by means of a circular disc that fits over and against the horizontal valve seat. The movement of the plane of disc is parallel to the normal direction of flow water through the orifice resulting to a tortuous passage which offers a high-pressure loss. Types of Globe Valve:

Conventional Type

Plug Type a. Plug Type b. Conventional Type c. Compression Type 3. Check Valve /No-return Valve / Reflux Valve – permit water to flow in one direction only. They are used in pump suction lines to prevent loss of water from the line when the pumped is stopped. This is known as foot valve. Ball type check valve is principally used in pumping sewage. - A valve that permits the flow of water within the pipe in only one direction and closes automatically to prevent backflow (the flow in a reverse direction).

Two types of Check Valve according to manner of installation: Plumbing Valves



a. Horizontal Check Valve b. Vertical Check Valve

Horizontal Check Valve

Vertical Check Valve

Types of Check Valve according to mechanism: a. Swing Check Valve

b. Lift Check Valve

Plumbing Valves



c. Ball Check Valve

d. Ball Valve – a valve in which the flow of liquid is controlled by a rotating drilled ball that fits tightly against a resilient or flexible seat in the valve body. A ball valve is basically a core cock with a spherical seat.

3. Angle Valve – a globe valve in which the inlet and outlet openings are at 90° angle to one

Butterfly Valve

Angle Valve another; used for individual plumbing fixture control such as lavatory, water closet etc. Plumbing Valves



5. Butterfly Valve – is now available with tight closure. It requires very little room and is easily manipulated and its use is increasing in piping of filter plants. - A valve with a rotating disk (the butterfly) that fits with the valve body. The rotation of the disk is by means of a shaft from the disk connected to the handle. 6. Backwater Valve – A type of check valve installed to prevent backflow of sewage from flooding the basement or lower floors of a building.

Types of Backwater Valve: a. Swing Backwater Valve b. Ball Type Backwater Valve 7. Pressure Reducing Valve /Pressure Regulating Valve – An automatic device used for converting inlet water pressure to a lower constant pressure. These automatically reduce pressure on the downstream side to any desired magnitude.

8. Relief Valve – A safety device that automatically provides protection against excessive temperatures, excessive pressures or both. This is installed in water heating equipment to protect from the dange of overheating and explosion. 9. Stop and Waste Valve – A type of compression stop valve with a side port into the valve body. This is used to control the flow of water to fixtures, such as sillcocks, that are subject to freezing.

Plumbing Valves



10. Foot Valve – A valve that is installed at the base or foot of the junction line of a pump in a water cistern or reservoir.

11. Float Valve – A valve used to control the water level in a tank or other container. It is operated by a float valve and the closing or opening which is dependent on the rise and fall of the float valve.

12. Flush Valve/Flushometer Valve – a valve used for flushing by using water directly from the water supply pipes or in connection with a special flush tank.

13. Mixing Valve – a valve which mixes liquid, by either automatic or manual regulation. Plumbing Valves



Mixing Valve Hydrant Valve 14. Hydrant Valve – consists of cast-iron barrel with a bell or f lange fitting at the bottom to connect to a branch from the water main. A valve in a hyd rant used for drawing water directly from the main; primarily used in connection with the protection or suppression system.

Other Miscellaneous Valves: Double Disc or gate type – it consists of a stem of brass or bronze which will resist corrosion. Altitude Valves – These are used to close automatically a supply line to an elevated tank when the tank is full. Automatic Poppet air valves – also known as air- and – vacuum valves, allow air to enter the pipe when it is emptied, thus preventing collapsing pressure from the outside atmosphere. Automatic Relief Valve- which will allow accumulated air to escape. Sluice Gate – are used to open or close openings into walls. Shear gates – are used for small circular openings. Sill cocks and Boiler Drains – are two types of compression stop valves. A sillcock is installed on the outside of a building so that a garden hose may b e attached. A boiler drain is a valve that is installed on a tank (such as a water heater) for draining and/or flushing. Boiler drains and sillcokcs are hearty identical, except that a sillcock has a mounting flange and the boiler drain has a screw threads for direct mounting onto a tank. Uses of Plumbing Valves: 1. A corporation cock is installed at the connection of water service to the water main. 2. A curb cock is located near the curb line of the building property to provide a means of controlling the water service to the building. 3. A full valve id installed before the water meter. 4. If necessary, a pressure reducing valve would be installed between the water meter v alves. 5. A relief Valve is installed on all hot water heating equipment. 6. A Full way valve is installed on the cold water supply. 7. A sill cock should be provided with a control valve located inside the building. 8. All water closets must have an individual control valve. Plumbing Valves



9. In apartment building, each family dwelling unit must be equipped with shutoff valve s controlling hot and cold water supply to that unit or the plumbing fixtures and appliances in that unit. Location of Full Open Valves 1. On the building water service from the public water supply near the curb. 2. On the water distribution supply pipe at the entrance into the structure. 3. On the discharge side of every water meter. 4. On the base of every water riser pipe which are two stories or more in height. 5. On top of every down feed pipe. 6. On the entrance to every water supply pipe to a dwelling unit, except where supplying a single fixture equipped with individual stops. 7. On the water supply pipe to a gravity or pressurized water tank. 8. On the waste supply pipe to every water heater. Location of Shut-off Valves: 1. On the fixture supply to each plumbing fixture i n all occupancies. 2. On the water supply pipe to each sillcock. 3. On the water supply pipe to each appliance or mechanical equipment. Code Provisions on the use of Plumbing Valves: 1. Valves up to and including 51 mm in size shall be brass or other approved materials. Sizes over 51mm in diameter may have cast iron or brass bodies. Each gate valve shall have a fullway type with working parts of non-corrosive materials. 2. A fullway valve controlling all outlets shall be installed on the discharge side of each water meter and on each unmetered water supply. Water Supply piping supplying more than one building in any premises shall be equipped with a separate fullway gate valve to each building, so arranged that the water supply can be turned on or off to any individual or separate building, provided that supply piping to a single family residence and building accessory thereto, may be controlled by o ne gate valve, Such shut off valve shall be accessible at all ti mes. 3. A valve used to control two (2) or more openings shall be fullway gate valve. 4. Control gate valves shall be installed before each water-supplied appliance slip joint, supply pipings for non-metallic fixture and appliance. 5. All required shutoff valves shall be accessible. 6. A single control gate valve is installed in a water supply line ahead of any automatic metering valve which supplies a battery of fixtures.

Plumbing Valves


Plumbing Valves

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