Z45 and Z41 are two common types of gate valves, with key differences in structural form, seal type, and applicable scenarios, detailed as follows:

I. Model Structure and Core Differences

1. Z41 Series (Rising Stem Gate Valves)

• Hard seal versions (e.g., Z41H) comply with standards such as GB/T 12234 (Power Station Valves) and are commonly used in petrochemical industries and high-temperature pipelines.

• Soft seal versions (Z41X) meet standards like CJ/T 216 (Resilient Seated Gate Valves) and are widely used in municipal water supply and building fire protection systems.

• Hard Seal (e.g., Z41H, Z41Y): The sealing surface uses metal materials such as stainless steel and hard alloy, featuring wear resistance and high-temperature resistance (up to 425℃ or higher). Suitable for working conditions involving high-pressure steam, oil products, etc.

• Soft Seal (e.g., Z41X): The gate plate is fully coated with rubber (e.g., EPDM, nitrile rubber). It achieves zero leakage through rubber elasticity, with better sealing performance than hard seals but lower temperature resistance (usually ≤80℃). Applicable to water supply and drainage, sewage treatment, and other normal-temperature, low-pressure scenarios.

• Structural Features: Adopt a rising stem design, where the stem is exposed and moves up and down with the gate plate. The valve opening can be directly judged by observing the extension length of the stem.

• Seal Types:

• Standards and Applications:

2. Z45 Series (Non-Rising Stem Gate Valves)

• Soft seal versions (Z45X) implement standards such as GB/T 12232 (General Gate Valves) and are often used in municipal pipe networks and agricultural irrigation.

• Hard seal versions (Z45H) comply with standards like GB/T 12234 and are applicable to high-temperature and high-pressure environments in chemical and power industries.

• Soft Seal (e.g., Z45X): The gate plate features an all-rubber coating design, with rubber vulcanized with a metal skeleton, offering corrosion resistance and reliable sealing. Suitable for fluids containing impurities such as sewage and seawater.

• Hard Seal (e.g., Z45H): The sealing surface is made of metal materials (e.g., stainless steel), resistant to high temperatures and pressures, and can be used in steam and oil pipelines but requires regular maintenance to prevent leakage.

• Structural Features: Adopt a non-rising stem design, where the stem is hidden inside the valve body. The gate plate is lifted and lowered by rotating the handwheel, resulting in a compact overall structure that saves installation space, especially suitable for buried or space-constrained scenarios.

• Seal Types:

• Standards and Applications:

• Soft seal versions (Z45X) implement standards such as GB/T 12232 (General Gate Valves) and are often used in municipal pipe networks and agricultural irrigation.

• Hard seal versions (Z45H) comply with standards like GB/T 12234 and are applicable to high-temperature and high-pressure environments in chemical and power industries.

II. Comparison of Key Parameters and Applicable Scenarios

III. Design Advantages and Manufacturing Standards

1. Z41 Rising Stem Gate Valves

• Hard Seal Versions: Stems are made of stainless steel (e.g., 2Cr13), paired with bronze nuts for self-lubrication, resulting in low opening/closing torque and corrosion resistance.

• Soft Seal Versions: The gate plate is 100% covered with rubber, using a dual-mold rubber injection vulcanization process. The sealing surface has no exposed points, complying with hygiene standards (e.g., GB/T 17219).

2. Z45 Non-Rising Stem Gate Valves

• Soft Seal Versions: Valve bodies are mostly made of ductile iron, with smooth flow channels to prevent dirt accumulation. An O-ring seal is installed between the stem and packing to prevent medium leakage.

• Hard Seal Versions: The sealing surface is overlay-welded with hard alloy, featuring a self-sealing design for the middle flange. The higher the pressure, the more reliable the sealing, suitable for high-pressure classes such as Class 150~600.

IV. Selection Recommendations

1. Prioritize Z41 Rising Stem Gate Valves:

• Scenarios requiring direct observation of valve opening (e.g., pump rooms, surface-mounted pipelines).

• High-temperature and high-pressure working conditions (hard seal) or clean water systems with strict sealing requirements (soft seal).

2.Prioritize Z45 Non-Rising Stem Gate Valves:

• Buried installations or pipelines with limited space (e.g., municipal pipe networks, valve wells).

• Fluids containing impurities (e.g., sewage) or low-pressure scenarios requiring frequent opening/closing (soft seal).