Heat exchanger temperature is generally controlled with ( ).

After installing ( ) on the pressure vessel, the pressure value of the medium in the vessel can be measured directly.

The safety drainage unit with better sealing performance, faster decompressionreaction, and less influence of dirt contained in the gas is ( ).

The drain unit for single use is ( ).

When the pressure in the pressure vessel exceeds the normal working pressure, it can be automatically opened to discharge part of the gas in the container, and when the pressure is reduced to the normal working pressure, it can be automatically closed to ensure that the pressure vessel does not cause accidents due to overpressure operation ( ).

The valve disc is driven by the valve stem and moves up and down along the axis of the sealing surface of the valve seat to achieve the purpose of opening and closing, called ( ).

Medium pressure valves are valves of nominal pressure ( ).

Not the valve model number that should normally be represented by the element is ( ).

Normal temperature valves are those that are resistant to medium operating temperature ( ).

The dynamic pressure seal can be divided into ( ) four types according to the lubrication state between the friction surfaces.

A pump with a fully enclosed seal is ( ).

The contact seal is ( ).

The non-contact seal is ( ).

According to the "fixed person" in the lubricating oil "five fixed", the lubrication of the bearing box of the machine pump shall be responsible for maintaining the oil level by ( ).

The injection amount of lubricating oil is generally controlled in the bearing box liquid level gauge ( ).