1.1 The manufacturing process is rough and the appearance is not beautiful.

1.2 Poor sealing: serious water leakage, not only waste of water resources, but also increased the burden of water bills on users;

1.3 Poor material quality: low strength and easy to rust, the valve handle wheel is broken when opened, the valve stem is twisted off, and the valve body has cracks;

1.4 Serious corrosion: difficult to open, unable to open, not closed tightly

Brass, which can automatically respond to system signals or be driven by the energy of the pipeline medium, is set to control the water flow direction and water equipment in different parts of the pipeline system, the pressure, temperature, opening status of the water production equipment, or the flow, pressure, and temperature of the medium in the pipe. Valves, such as pressure reducing valves, pressure sustaining valves, brass control valves, brass check valves, etc.

2.2.1 Brass valve for adjustment

A brass valve set to make the flow of water delivered in a certain part of the pipeline system meet the design requirements. Such as regulating valve, pressure reducing valve, throttle valve, constant flow valve, flow brass control valve, automatic temperature regulating valve, etc.

2.2.2. Special purpose brass valve

Brass valves installed in special parts of the piping system. Such as exhaust valve, sludge discharge valve, metering valve, water injection valve, steam trap, etc.

2.2.3 Special brass valve

Refers to brass valves used in fire water supply systems, such as various alarm valves, signal valves, water flow indicators, etc.

Brass valves, such as safety valve, pressure relief valve, pipeline backflow preventer, explosion-proof wave valve, safety valve, water hammer eliminator, emergency Close the valve, etc.

2.4.1 Low pressure brass valve: the working pressure is 0.6-1.6MPa.

2.4.2 Medium pressure brass valve: the working pressure is 1.6-2.5Mpa.

2.4.3 High pressure brass valve: the working pressure is 40Mpa and above.

In the water supply and drainage system of buildings, low-pressure small and medium-sized (DN≤200mm) brass valves are the most widely used basic products.

Brass valve selection points small size and light weight.

In order to reduce the size of the brass valve well outdoors, because of the relative concentration of various professional pipes in the building and the limited floor height of the building, in order to meet the effective space of the indoor room, the brass valve with small size and light weight is the first choice. For the water supply and drainage pipeline systems that are often opened and closed in the building department, brass gate valves and brass globe valves made of copper or stainless steel should be used. Due to the infrequent opening of fire water supply pipelines, ductile iron brass gate valves or brass butterfly valves should be used. Brass butterfly valve with locking device.

Flexible opening, wear resistance and long service life

Small brass valves in front of water equipment and appliances in buildings are frequently used, and their flexibility and durability are important considerations. It is better to choose brass globe valve made of copper and stainless steel with good corrosion resistance.

The valve cavity of the brass valve has a large effective water section, and the surface is smooth and the resistance is small, and no slag remains during the water flow process. Good sealing performance. The requirement of no water leakage in the building is very important, not only to not damage the decoration, but also to save the water cost for the user and save the water resources for the country. Brass globe valve, brass gate valve and brass ball valve all have this advantage. However, the brass ball valve is easy to produce water hammer due to its rapid opening and closing, so it should be used as little as possible. The elastic seated brass gate valve has the function of deformation compensation, and the sealing effect is good.

The building water supply and drainage system transports drinking water, which is directly related to people's drinking water safety. Therefore, the coating of brass valves must meet the requirements of "Safety Evaluation Standards for Drinking Water Transmission and Distribution Equipment and Protective Materials". Therefore, in the design description, it should be clearly stated that the certification certificate of the "Product and Sanitation Supervision Department" can be used.

3.2.1 Direction of water flow

In order to keep the water flow resistance of the annular water supply network small and the flow rate unchanged when flowing in the forward and reverse directions, brass gate valves and brass butterfly valves should be used. Brass shut-off valve with adjustable flow can be used for branch pipe network. Brass check valves are used for pipe sections that may affect equipment and instruments when the water is returned.

3.2.2 Installation direction

Due to the limitation of space inside the building, the operation requirements should be considered, so that the valve stem can be installed in the horizontal direction or vertically downward.

The working pressure of the valve body should meet the requirements that the system will not be damaged under the design water supply pressure, and there should be a certificate of conformity.

Brass valves with a pipe diameter less than or equal to 50mm are generally installed on sanitary ware, water equipment (water heaters, water boilers, water tank supplementary water and water heaters, etc.), and water distribution branches of household water meters. Brass valves in these parts are frequently opened and closed, so copper and stainless steel materials with good corrosion resistance should be the best.

Brass valves with a pipe diameter greater than 50mm are generally installed on the main water distribution pipes. The opening and closing of brass valves is not frequent, so ductile iron or cast steel valve bodies, copper valve stems, and high-strength cast aluminum copper ( Brass valves with brass or bronze) nuts are preferred.

Brass valves on pipelines conveying special liquids (pure water, desalinated water, acid-base solutions, etc.) are preferably stainless steel ABS plastic brass valves and polyethylene plastic brass valves of corresponding brands.

The seal is preferably double-seal structure, O-ring, and internal oil lubrication.

Flexible seals, such as silicone rubber, butadiene rubber, flexible graphite, polyphenylene, polytetrafluoroethylene, etc., are elastic, and have the advantages of wear resistance, high temperature resistance, aging resistance, extrusion resistance and non-deformation. The building water supply and drainage system is better to choose a flexible and sealed brass valve that is easy to maintain.

Stem packing requires durability and long replacement cycle, aging resistance, high temperature resistance, wear resistance and small wear. PTFE and flexible graphite are the best, followed by rubber and rubber graphite.

The inner lining or inner coating material should be non-toxic and corrosion-resistant material, and meet the requirements of "Sanitary Requirements for Drinking Water" (details in Section 3, Item 4 of this article), and the surface is smooth and the water flow resistance is small. The coverage should be comprehensive and perfect, without affecting the sealing effect, and can prevent the electrochemical corrosion of different materials.

When the maintenance function is the main

For cold water pipelines, it is better to use brass gate valves with small water flow resistance. The household water distribution branch pipe is preferably a brass globe valve. If the diameter of the pipe is large and the installation space limitation cannot choose the brass gate valve, it is better to choose the brass butterfly valve.

A brass gate valve must be selected on the suction pipe of the fire-fighting water supply pressure pump. In addition to the small resistance factor, the function of directly observing its open and closed state from the protruding height of the valve stem is also considered.

It is better to choose brass globe valve or regulating valve for hot water pipeline, its purpose is to meet the requirement of one-way regulation of water supply, so as to achieve the balance of hot water in the system.

When the control function is the main:

temperature control

a Water heater should choose an automatic temperature control valve. The facility is simple and reliable, but not very precise. It is understood that the control accuracy range is ± 2 ℃, but it can meet the requirements of domestic hot water system.

b For systems with higher precision requirements for the outlet water temperature of heaters or hot and cold water mixers, it is better to use electric temperature control valves.

a In order to ensure the balance of water pressure in the pipeline system, prevent the loss of water appliances caused by excessive pressure, and ensure the stable operation of water appliances

In order to improve the service life and save water, an adjustable pressure reducing valve or pressure reducing valve should be installed.

b The pipeline system does not require high pressure fluctuations (that is, the pressure behind the valve is allowed to fluctuate), but for the fire-fighting water supply pipeline system that requires stable flow, it is best to use a proportional pressure reducing valve, and its pressure reduction ratio is not greater than 3:1: it is good.

c For the domestic water supply system that requires stable outlet pressure and flow, choose a pressure reducing regulator or an adjustable pressure reducing valve that can achieve the purpose of decompression and stability; however, when an adjustable pressure reducing valve is selected, in order to ensure the use effect and lifespan, According to the system requirements of this type of brass valve, the pressure difference before and after the valve is preferably 0.3MPa or 0.4MPa. 

a The automatic sprinkler piping system should select different types of alarm valves and signal valves that can display the opening and closing status of brass valves according to the system functions.

b When it is necessary to know the water flow and water pressure status in the pipe at any time in the automatic water spray system and other pipeline systems, the water flow indicator and pressure controller should be selected.

a. Floating brass ball valve

When the water enters the pool or water tank through the valve body, the float ball rises or falls with the water level in the pool or the tank, driving the valve stem to rise or fall to close or open the brass valve to supply water or cut off the water in the container. It is directly installed in the water tank (pool), so the space in the box (pool) is relatively large.

b. Hydraulic water level brass control valve

The small-diameter floating brass ball valve installed in the water tank (pool) is used to control the up-and-down movement of the water level.

The main valve outside is opened and closed to achieve the purpose of supplying and cutting water to the water tank (pool). The main water inlet pipe can pass from the top of the tank (pool)

It can also enter from the lower part of the side wall. When the latter is used, a backflow preventer must be installed before the main valve.

4.8.1 Flow balance valve

For example, when the water flow in the pipeline is limited within the set value range, to achieve the purpose of intercepting, throttling and regulating the flow,

This valve is optional. Generally, when the piping arrangement of the domestic hot water system cannot be done in the same way, this valve can be selected to realize the dynamic balance of the system.

4.8.2 flow brass control valve

Adjust the water pump or the main pipe to supply the brass valve with the set flow to other pipe networks and branch pipes. For example, a swimming pool is equipped with a set of water purification facilities, but when supplying several recreational pools with different usage requirements, the water supply pipes and distribution pipes for different pools are supplied. This brass valve should be installed on each branch water supply pipe on the water heater, so that it will not be affected by the pressure change before and after the valve.