【Q&A Question 111】April 21, 2018
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【Q&A Question 111】April 21, 2018: Briefly explain what the opening pressure and reset pressure of a safety valve are The opening pressure of a safety valve is divided into the initial opening pressure and the full opening pressure. The initial opening pressure is usually referred to as the opening pressure of the safety valve. Once the safety valve opens, the medium inside the container begins to be discharged. When the pressure of the medium drops to the lower limit of the initial opening pressure, the safety valve closes and maintains a good seal, allowing the container to function properly. The pressure at which the safety valve closes is known as the return pressure. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) The validity period for this question is 48 hours; within those 48 hours, 10 wealth points are awarded for correct answers and 2 wealth points for incorrect answers ； If the response is given after 48 hours, the score is halved, regardless of whether it is correct or not ； Mass posting of posts – rated based on the lowest score ； Replies that are unrelated to the answer are considered spam and will be deleted immediately. For management purposes, if you need to view content from a few days ago, please go to https://bbs.hcbbs.com/home.php?mod=space&uid=3862647&do=thread&view=me&from=space through the summary post below. The APP short-video skills competition has begun! https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1951670
The pressure at which the valve seat moves away from the sealing surface is called the opening pressure, while the pressure at which the valve seat returns to the sealing surface is called the closing pressure.
Opening pressure: The inlet pressure at which the safety valve disc begins to rise under operating conditions (or during testing on a testing device). The reset pressure of a safety valve refers to the static pressure at the inlet of the safety valve when, after it has started to discharge, the system pressure decreases, causing the valve disc to come into contact with the valve seat again; at this point, the valve’s opening height is zero and the flow of fluid ceases.
Opening pressure: Also known as rated pressure or set pressure, it refers to the inlet pressure at which the valve disc of a safety valve begins to rise under operating conditions. At this pressure, a measurable opening height is achieved, and the fluid starts to be discharged in a manner that can be detected visually or audibly. Seat back pressure: The inlet pressure when the valve disc comes into contact with the valve seat again after discharge, that is, when the opening height becomes zero.
The opening pressure of a safety valve is the pressure at which the valve disc begins to rise, allowing the material to flow out continuously. The return pressure is the pressure at which the safety valve returns to its normal position after it has activated.
Answer: The opening pressure of a safety valve is divided into the initial opening pressure and the full opening pressure. The initial opening pressure is usually referred to as the opening pressure of the safety valve. Once the safety valve opens, the medium inside the container begins to be discharged. When the pressure of the medium drops to the lower limit of the initial opening pressure, the safety valve closes and maintains a good seal, allowing the container to function properly. The pressure at which the safety valve closes is known as the return pressure.
The opening pressure of a safety valve is divided into the initial opening pressure and the full opening pressure. The initial opening pressure is usually referred to as the opening pressure of the safety valve. Once the safety valve opens, the medium inside the container begins to be discharged. When the pressure of the medium drops to the lower limit of the initial opening pressure, the safety valve closes and maintains a good seal, allowing the container to function properly. The pressure at which the safety valve closes is known as the return pressure.
Opening pressure: also known as set pressure, it is the pressure of the medium at which the valve disc of a safety valve begins to rise under operating conditions. Seat back pressure: The inlet pressure at which the valve disc presses back against the seat after the safety valve has discharged, and flow stops. The return seat pressure is an important parameter that indicates the quality of a safety valve’s performance; it is generally required to be at least 80% of the operating pressure, with an upper limit set such that the valve disc does not experience frequent oscillations.
The opening pressure of a safety valve is the pressure at the inlet of the valve when its disc begins to move upward. It is also called set pressure. After the safety valve opens, when the pressure of the medium drops to a certain value, the valve closes and maintains a good seal, allowing the container to function properly; this pressure value is known as the reset pressure.
Opening pressure: also known as set pressure, it is the pressure of the medium at which the valve disc of a safety valve begins to rise under operating conditions; closing pressure is the pressure at which the safety valve returns to its original position after it has opened
The opening pressure is the pressure at which the safety valve is set to activate, as determined by humans. The return pressure is the pressure at which the safety valve returns to its original position after it opens. For example: A pressure vessel has a normal operating pressure of 1.0 MPa, with a set pressure for its safety valve at 1.04 MPa and a return pressure of 0.98 MPa. So: when the internal pressure of this pressure vessel is ≤ 1.04 MPa, the safety valve does not activate ； When the pressure exceeds 1.04 MPa, the safety valve activates; this causes the pressure to drop. However, even when the pressure falls to the normal level of 1.0 MPa, the safety valve may not return to its original position and continues to discharge steam. It is only when the pressure drops further to 0.98 MPa that the safety valve returns to its original position and stops discharging steam.