The maximum allowable working pressure of a valve decreases as the temperature of the medium increases. A pressure-temperature rating table is typically provided on the valve nameplate or product catalog.
Important Note: Never infer the pressure resistance of a valve at high temperatures based solely on a PN16 pressure rating at room temperature (e.g., Class 150). Always refer to the maximum allowable working pressure at the corresponding temperature. Key points to consider when selecting a knife gate valve based on pressure:
Confirm the operating pressure: Identify the system's maximum operating pressure and temperature.
Select the appropriate pressure rating: Based on the operating pressure and temperature, select a knife gate valve with adequate pressure-temperature ratings (consult the P-T table). For typical applications such as slurry and wastewater, ANSI 150# / PN16 is generally an adequate and economical choice.
Avoid overpressure: Using a knife gate valve in conditions exceeding the valve's rated pressure (at the corresponding temperature) is strictly prohibited; this poses a serious safety hazard.
Consider the media characteristics: If the media contains hard particles or is highly abrasive, high pressure will increase wear on the sealing surface and gate, further reducing sealing performance and service life.
Summary:
• When selecting a knife gate valve, it is essential to select a model with adequate pressure-temperature ratings based on the system's actual maximum operating pressure and temperature, and strictly avoid overpressure use.
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