sekedar sharing ..
saat ini juare97 sedang mempelajari VPSV (Vacuum Pressure Safety Valve) lebih dalam.
bahan-bahannya dari standard, wikipedia, dll.
Berikut bacaan yang dipakai:
- API Standard 2000 – Venting Atmospheric and Low-Pressure Storage
- API RP 576 – Inspection of Pressure Relieving Devices
- API Standard 527 – Seat Tightness of Pressure Relief Valves
- API RP 520 Part I & Part II – Sizing, Selection & Installation of Pressure
Relieving in Refineries.
- API RP 521 – Guide for Pressure Relieving & Depressuring.
- wikipedia: http://en.wikipedia.org/wiki/Safety_valve
- wikipedia: http://en.wikipedia.org/wiki/Relief_valve
- Groth Corporation – Installation, Operation and Maintenance Manual for Pressure/Vacuum Relief Valves – Models 1800A, 1810A, 1820A, 1830A, 1860A, 1870A
- dan lain-lain.
sekilas di cuplik dari wikipedia: (terjemahin sendiri yah 😉 )
A safety valve is a valve mechanism which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits.
It is one of a set of pressure safety valves (PSV) or pressure relief valves (PRV), which also includes relief valves, safety relief valves, pilot-operated relief valves, low pressure safety valves, and vacuum pressure safety valves.
Vacuum safety valves (or combined pressure/vacuum safety valves) are used to prevent a tank from collapsing while it is being emptied, or when cold rinse water is used after hot CIP (clean-in-place) or SIP (sterilization-in-place) procedures
In the petroleum refining, petrochemical, chemical manufacturing, natural gas processing, power generation, food, drinks, cosmetics and pharmaceuticals industries, the term safety valve is associated with the terms pressure relief valve (PRV), pressure safety valve (PSV) and relief valve. The generic term is Pressure relief valve (PRV) or pressure safety valve (PSV) It should be noted that PRVs and PSVs are not the same thing, despite what many people think; the difference is that PSVs have a manual lever to open the valve in case of emergency.
- Relief valve (RV): an automatic system that is actuated by the static pressure in a liquid-filled vessel. It specifically opens proportionally with increasing pressure.
- Safety valve (SV): an automatic system that relieves the static pressure on a gas. It usually opens completely, accompanied by a popping sound.
- Safety relief valve (SRV): an automatic system that relieves by static pressure on both gas and liquid.
- Pilot-operated safety relief valve (POSRV): an automatic system that relieves on remote command from a pilot, to which the static pressure (from equipment to protect) is connected[clarification needed].
- Low pressure safety valve (LPSV): an automatic system that relieves static pressure on a gas. Used when the difference between the vessel pressure and the ambient atmospheric pressure is small.
- Vacuum pressure safety valve (VPSV): an automatic system that relieves static pressure on a gas. Used when the pressure difference between the vessel pressure and the ambient pressure is small, negative and near to atmospheric pressure.
- Low and vacuum pressure safety valve (LVPSV): an automatic system that relieves static pressure on a gas. The pressure is small, negative or positive, and near to atmospheric pressure.
RV, SV and SRV are spring-operated (even spring-loaded). LPSV and VPSV are spring-operated or weight-loaded.
info dari salah satu manufacture VPSV – Groth Corporation – Installation, Operation and Maintenance Manual for Pressure/Vacuum Relief Valves – Models 1800A, 1810A, 1820A, 1830A, 1860A, 1870A :
Pressure and/or vacuum relief valves are used on liquid storage tanks and other process vessels or systems to prevent structural damage due to excess internal pressure or vacuum.
Storage tanks are pressurized when liquid is pumped in, compressing the existing vapor or when rising temperatures cause increased evaporation or expansion of existing vapor. Conversely, a vacuum condition may be created when pumping out or due to falling temperature. To prevent tank damage, vapor must be allowed into or out of the tank at specified pressure/vacuum conditions. The volume rate of venting depends upon the tank size, volatility of the tank contents, the pumping rates and the temperature. Refer to API Standard 2000, ISO 28300, or local regulations for the procedures to determine venting requirements.
A relief valve must be carefully maintained by a qualified valve technician. It should only be assembled under clean conditions, preferably in a service shop environment. Carefully read and understand this manual before installing or attempting to repair a valve.
Tank protection equipment typically includes an operating valve which is designed to provide pressure/vacuum relief under normal pump in/out and thermal breathing conditions. An emergency relief valve can also provide both pressure and vacuum relief and normally it is sized to provide pressure relief if there is a fire in the immediate vicinity of the tank. It may also be sized by the tank designer to provide protection in the event of equipment failure (such as the rupture of a process steam line or an inert gas blanketing system failing open) or operator error..
A typical tank installation is shown in Figure 1 which includes the following Groth products:
- Model 1820A Pressure/Vacuum Weight Loaded Valve
- Model 3011H Gas Blanketing Regulator
- Model 2400A Emergency Pressure Relief Valve
Pressure Relief: As the pressure in the storage tank increases, the vacuum pallet is held shut. When the set pressure is reached, the pressure pallet lifts and relieves tank pressure to the atmosphere (or to a header if it is a pipe away valve). See Figure 2.
Vacuum Relief: As a vacuum is drawn in the storage tank (for example, when fluid is being pumped out), the pressure pallet is held shut. When the vacuum setting is reached, the vacuum pallet lifts and air is drawn into the tank from the atmosphere. See Figure 3.
Contoh photo VPSV..
sumber: TECHNICAL BRIEF – Full Lift Type Valve at 10% Overpressure – 1800A Series
kalau Merek lain: Tycovalves – Varec
Sumber: Varec 2010B/2020B – Pressure and Vacuum Relief Valve
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