Blocks Of Safety Relief Valves With Change-Over Valves
A safety device consisting of two safety valves and a switching device in the form of a three-way valve, ensuring a permanent connection of the equipment protected from unacceptable overpressure to only one of the safety valves.
Switching between the two installed safety valves allows one safety valve to always perform its function while the other valve is being serviced.
Technical specifications
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Nominal diameter DN 25 to 250 mm
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Operating temperature - 196 to 500 °C
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Body material carbon steel / stainless steel / cold-resistant steel / heat-resistant steel / corrosion-resistant alloys
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Type of connection flanged
Execution options
With soft seat
Soft seat design (seat tightness at an operating pressure equal to 95% of the set pressure)
With bellows stem seal
It is designed for installations with high requirements for tightness and safety. The tightness is achieved due to the metal bellows, which completely eliminates the release of the working medium into the atmosphere, even during prolonged operation. The bellows operates under external pressure and is protected by guide bushings that provide resistance to vibrations and pressure drops. This design is optimal for toxic, explosive and vacuum environments where leakage is unacceptable, and guarantees durability, reliability and maintenance-free stuffing box assembly.
For hydrogen sulfide service
In accordance with the requirements of the NACE MR 0103/01-75 standard for media containing hydrogen sulfide
Hardfacing of the trim parts
The use of coatings based on carbides and alloys (tungsten carbide, stellite, etc.) increases wear resistance and abrasion resistance, ensuring long-term tightness and service life under severe operating conditions.
With a chain wheel transmission / universal joint
A chain wheel transmission or universal joint ensures the convenience in space-limited environment, while maintaining the ease and accuracy of valve control.