ASME Section IV Pressure Relief Valves and Devices
18 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the maximum pressure at which a safety valve for a steam boiler should discharge, according to ASME BPVC, Section IV?

  • 25 psi
  • 15 psi (correct)
  • 30 psi
  • 20 psi
  • What is the minimum size for a safety valve for a steam boiler according to ASME BPVC, Section IV?

  • NPS 1 (DN 25)
  • NPS ½ (DN 15) (correct)
  • NPS ¼ (DN 8)
  • NPS ¾ (DN 20)
  • What is the maximum allowable pressure rise for a steam boiler when the fuel burning equipment is operated at maximum capacity, according to ASME BPVC, Section IV?

  • 5 psi (correct)
  • 15 psi
  • 10 psi
  • 20 psi
  • What type of body drain connection should be provided for all safety valves and safety relief valves according to ASME BPVC, Section IV?

    <p>Below seat level</p> Signup and view all the answers

    What is the maximum allowable size for a safety valve for a steam boiler according to ASME BPVC, Section IV?

    <p>NPS 4 (DN 100)</p> Signup and view all the answers

    What is the minimum pressure at which a safety valve for a steam boiler should discharge, according to ASME BPVC, Section IV?

    <p>5 psi</p> Signup and view all the answers

    Where must safety valves and safety relief valves be located on a boiler?

    <p>In the highest practicable part of the boiler proper</p> Signup and view all the answers

    What is the requirement for the internal cross-sectional area of the discharge pipe for safety valves and safety relief valves?

    <p>It should be greater than the full area of the valve outlet</p> Signup and view all the answers

    Which type of safety valve is designed for low-pressure steam heating boilers?

    <p>Valve without adjustable blowdown ring</p> Signup and view all the answers

    According to ASME BPVC IV, Part HG-400.2, how many officially rated safety relief valves should a hot water heating or supply boiler have?

    <p>At least one officially rated safety relief valve</p> Signup and view all the answers

    What is the purpose of the body drain openings in a safety relief valve?

    <p>To release any accumulating condensate or liquid</p> Signup and view all the answers

    Why should the outlet of a pressure relief valve never be plugged?

    <p>To avoid corrosion and sticking of the safety valve</p> Signup and view all the answers

    What should be done if a long vertical discharge pipe is required for a safety valve?

    <p>Install a flexible joint near the safety valve</p> Signup and view all the answers

    What happens when a safety relief valve opens partially due to boiler pressure slightly exceeding the valve setting?

    <p>The slight flow of escaping water has no lifting effect on the valve lip</p> Signup and view all the answers

    What is one common cause for frequent safety relief valve operation?

    <p>Scale and corrosion accumulation on the valve seat</p> Signup and view all the answers

    What is the design difference between a safety relief valve and a safety valve used for steam boilers?

    <p>Safety relief valves are non-resettable, while safety valves have adjustable blowdown rings</p> Signup and view all the answers

    Why must hot water heating systems be isolated and drained if frequent safety relief valve operation occurs?

    <p>To remedy a waterlogged heating system causing frequent operation of the relief valve</p> Signup and view all the answers

    What component contains compressed air or nitrogen in a hot water heating system?

    <p>The expansion tank</p> Signup and view all the answers

    Study Notes

    ASME BPVC, Section IV: Safety Valve Requirements for Steam Boilers

    • Safety valves for steam boilers should discharge at a maximum pressure of 10% above the maximum allowable working pressure.
    • The minimum size for a safety valve for a steam boiler is 1/2 inch.
    • The maximum allowable pressure rise for a steam boiler when the fuel burning equipment is operated at maximum capacity is 10% of the maximum allowable working pressure.
    • All safety valves and safety relief valves should have a body drain connection of at least 1/4 inch.
    • There is no maximum allowable size for a safety valve for a steam boiler.
    • Safety valves for steam boilers should discharge at a minimum pressure of 10% above the maximum allowable working pressure.
    • Safety valves and safety relief valves should be located on the boiler and connected to the steam space or to the discharge pipe.

    Safety Valve and Safety Relief Valve Requirements

    • The internal cross-sectional area of the discharge pipe for safety valves and safety relief valves should be at least equal to the internal cross-sectional area of the valve inlet.
    • Low-pressure steam heating boilers require a specific type of safety valve designed for low-pressure service.
    • A hot water heating or supply boiler should have at least two officially rated safety relief valves.
    • The body drain openings in a safety relief valve serve to prevent water from accumulating in the valve.

    Safety Valve Installation and Operation

    • The outlet of a pressure relief valve should never be plugged to prevent fluid from accumulating and causing damage.
    • If a long vertical discharge pipe is required for a safety valve, it should be designed to mitigate the effects of back pressure.
    • If a safety relief valve opens partially due to boiler pressure slightly exceeding the valve setting, it will continue to open and close rapidly, wasting steam and potentially causing damage.
    • Frequent safety relief valve operation can be caused by a malfunctioning valve, inadequate valve sizing, or an undersized boiler.
    • The design difference between a safety relief valve and a safety valve used for steam boilers is that safety relief valves are designed for hot water heating or supply boilers, whereas safety valves are used for steam boilers.

    Hot Water Heating System Requirements

    • Hot water heating systems must be isolated and drained if frequent safety relief valve operation occurs to prevent damage and ensure safety.
    • The component that contains compressed air or nitrogen in a hot water heating system is the expansion tank.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Description

    Learn about the ASME Section IV requirements for pressure relief valves and devices, particularly in the context of heating boilers. This quiz covers the code requirements, construction, and operation of safety relief valves as per ASME BPVC Section IV.

    Use Quizgecko on...
    Browser
    Browser