The function of the valve seat: used to support the fully closed position of the valve core and form a sealing pair.

Function of Disc: Disc – a spherical disc that maximizes lift and minimizes pressure drop. Hardened to maximize service life.

The role of the valve core: The valve core in the pressure reducing valve is one of the main components for controlling pressure.

Valve seat characteristics: Corrosion and wear resistance; Long operating time; High pressure resistance; High dimensional accuracy; Excellent resistance to thrust loads and high temperatures; Suitable for most passenger cars, light and heavy trucks, diesel engines and stationary Industrial engines.

Valve disc features: It has an adjustable positioning function to prevent the valve body shell wall from being penetrated. The unique clamshell butterfly plate check valve has a built-in butterfly plate hinge pin, which not only eliminates the possibility of the hinge pin puncturing the valve housing for leakage, but also makes the valve seat easy to repair because the machined bracket is parallel to the valve seat surface. Adjust disc/seat.

Features of the valve core: When the rotating core rotates, the fork at the lower end of the rotating core drives the moving valve plate to rotate, so that the water outlet hole on the moving valve plate corresponds to the water inlet hole on the moving valve plate. static valve plate, and finally water flows out from the rotating core. Through-hole outflow, this design is widely used at faucet outlets.

Valve seat overview: Use elastic sealing material and smaller actuator thrust to obtain an airtight seal. The sealing stress of compressing the valve seat causes the material to elastically deform and squeeze into the rough surface of the mating metal component to plug any leaks. path. The permeability of materials to fluids is the basis for small leaks.

Valve disc overview: skirt type disc sealing ring. The utility model discloses a skirt-type valve disc sealing ring. Its structural feature is that the seal between the sealing ring and the valve disc body is a double-edged line seal. The longitudinal section at the sealing point between the sealing ring and the valve disc body is a trapezoidal plane space.

Valve core overview: The valve core is a valve part that uses the movement of the valve body to achieve the basic functions of direction control, pressure control or flow control.

The detachable end face part in the valve is used to support the fully closed position of the valve core and form a sealing pair. Generally, the valve seat diameter is the maximum flow diameter of the valve. For example, butterfly valves come in a variety of seat materials. The valve seat material can be made of various rubber, plastic, and metal materials, such as: EPDM, NBR, NR, PTFE, PEEK, PFA, SS315, STELLITE, etc.

Material properties that should be considered when selecting a soft valve seat are:
1) Fluid compatibility, including swelling, hardness loss, permeability and degradation;
2) Hardness;
3) Permanent deformation;
4) The degree of recovery after removing the load;
5) Tensile and compressive strength;
6) Deformation before rupture;
7) Elastic modulus.

Disc

The valve disc is the valve core, which is one of the main core parts of the valve. It directly bears the medium pressure in the valve. The materials used must comply with the “Valve Pressure and Temperature Class” regulations.

Commonly used materials include the following:
1. Gray cast iron: Gray cast iron is suitable for water, steam, air, gas, oil and other media with a nominal pressure PN ≤ 1.0MPa and a temperature of -10°C to 200°C. Commonly used grades of gray cast iron are: HT200, HT250, HT300, and HT350.
2. Malleable cast iron: suitable for water, steam, air and oil media with nominal pressure PN≤2.5MPa and temperature of -30~300℃. Commonly used grades include: KTH300-06, KTH330-08, KTH350-10.
3. Ductile iron: suitable for water, steam, air, oil and other media with PN≤4.0MPa and temperature -30~350℃. Commonly used grades include: QT400-15, QT450-10, QT500-7.
In view of the current domestic technical level, various factories are uneven, and user inspections often have difficulties. Based on experience, it is recommended that PN≤2.5MPa and the valve material should be steel to ensure safety.
4. Acid-resistant high-silicon ductile iron: suitable for corrosive media with nominal pressure PN ≤ 0.25MPa and temperature below 120°C.
5. Carbon steel: suitable for media such as water, steam, air, hydrogen, ammonia, nitrogen and petroleum products with a nominal pressure PN ≤ 32.0MPa and a temperature of -30 ~ 425°C. Commonly used grades include WC1, WCB, ZG25, high-quality steel 20, 25, 30 and low-alloy structural steel 16Mn.
6. Copper alloy: suitable for water, seawater, oxygen, air, oil and other media with PN≤2.5MPa, as well as steam media with a temperature of -40~250℃. Commonly used grades include ZGnSn10Zn2 (tin bronze), H62, Hpb59-1 (brass), QAZ19-2, QA19-4 (aluminum bronze).
7. High temperature copper: suitable for steam and petroleum products with nominal pressure PN≤17.0MPA and temperature ≤570℃. Commonly used grades include ZGCr5Mo, 1Cr5M0, ZG20CrMoV, ZG15Gr1Mo1V, 12CrMoV, WC6, WC9 and other grades. Specific selection must comply with valve pressure and temperature specifications.
8. Low-temperature steel, suitable for nominal pressure PN≤6.4Mpa, temperature ≥-196℃ ethylene, propylene, liquefied natural gas, liquid nitrogen and other media, commonly used brands) include ZG1Cr18Ni9, 0Cr18Ni9, 1Cr18Ni9Ti, ZG0Cr18Ni9 9. Stainless steel acid-resistant steel, suitable For nominal pressure PN≤6.4Mpa, temperature ≤200℃ nitric acid, acetic acid and other media, commonly used brands are ZG0Cr18Ni9Ti, ZG0Cr18Ni10<nitric acid resistance>, ZG0Cr18Ni12Mo2Ti, ZG1Cr18Ni12Mo2Ti<acid and urea resistance>

valve core
The valve core is a valve part that uses its movement to achieve the basic functions of direction control, pressure control or flow control.

Classification
According to the movement mode, it is divided into rotation type (45°, 90°, 180°, 360°) and translation type (radial, directional).
According to the shape, it can generally be divided into spherical (ball valve), conical (plug valve), disc (butterfly valve, gate valve), dome-shaped (stop valve, check valve) and cylindrical (reversing valve).
Generally made of bronze or stainless steel, there are also plastics, nylon, ceramics, glass, etc.
The valve core in the pressure reducing valve is one of the main components for controlling pressure.