Discussion on the Layout of Safety Valve and Its Piping Design
Discussion on the Layout of Safety Valve and Its Piping Design
The safety valve is the best overpressure protection device on the pressure equipment, the container and the pipeline. When the medium pressure rises above the allowable value, the safety valve will automatically open and then the total discharge will prevent the pressure from rising, thus protecting the equipment and its operation Personnel safety; when the pressure down to the specified value, the safety valve automatically closed in time to prevent the media continue to discharge, reduce losses. Since the safety valve is an automatic valve, it is often used as the last protection device for the pressurized device. In this sense, its role can not be replaced by other protective devices.
The safety valve should be mounted upright and as close as possible to the protected equipment or pipe. If not close to the arrangement, the total pressure drop from the protected equipment or pipe to the inlet of the safety valve shall not exceed 3% of the safe value of the safety valve or 1/3 of the maximum allowable opening and closing pressure Whichever is smaller), the pressure drop over the General Assembly will cause the safety valve to take off frequently. Engineering practice commonly used to reduce the pressure drop approach by the appropriate expansion of the safety valve inlet diameter, the use of long radius elbow, reduce the number of elbows to reduce the total pressure drop pipe.
Safety valve installation location should be mainly considered easy maintenance. Therefore, the safety valve should be set up maintenance platform, which can facilitate the piping is also easy to regularly check the safety valve, maintenance and calibration work. When arranging a heavy safety valve, consider the possibility of lifting the relief valve after disassembly. If necessary, install the boom and the site and space for the maintenance of the inspection. Engineering practice, the common practice is to install the safety valve in the top of the tube. In this way, on the one hand, higher than the venting manifold, on the other hand the safety valve is arranged on the top of the pipe to facilitate maintenance.
If it is difficult to install on the container body for special reasons, it may be considered to be installed on the outlet pipe. However, the pipe between the safety valve installation and the container should avoid sudden bending and partial shrinkage. Resistance, causing the accumulation of dirt clogging and so on.
Second, the safety valve inlet pipe design
The minimum cross-sectional area of the channel of the inlet pipe shall not be less than the inlet cross-sectional area of the safety valve. For high pressure and large displacement applications, the inlet pipe should have a sufficiently large fillet radius at the inlet; or a tapered channel, the inlet cross-sectional area of the tapered channel is approximately twice the outlet cross-sectional area.
Third, the safety valve outlet piping design
Safety valve outlet pipe design should consider the back pressure does not exceed the constant value of the safety valve. For ordinary spring-type safety valve, the back pressure does not exceed 10% of the safety valve constant pressure.
The outlet pipe of the safety valve discharged into the torch should be diverted to the top of the discharge manifold at a distance of 45 ° to prevent the condensate from flowing into the manifold and reduce the back pressure of the safety valve.
As the material is discharged, the discharge of the material will produce a certain force on the discharge pipe and through the discharge pipe to the safety valve, the resulting force and torque will be the equipment nozzle and safety valve inlet and outlet pipes have a negative impact, and even cause Safety valve seal leaked accident. It should be the safety valve outlet reaction calculation, and consider their own weight, vibration, wind load, thermal expansion and contraction factors such as set the appropriate support.
Fourth, the safety valve before and after the cut off valve and bypass valve settings
1. Set the valve before and after the safety valve
In the production, the safety valve replacement, the equipment is not necessarily cut off, so most enterprises in order to ensure production, in the safety valve before the installation of shut-off valve. The general should use a single gate valve, and sealed, the stem should be installed horizontally, so that the valve stem and valve plate connected to the corrosion or loose when the valve plate down. When the safety valve test expires, after the break after the break, you can close the safety valve inlet shut-off valve, remove the safety valve for calibration or replacement. According to the actual production experience, the main situation before the installation of the main closure valve:
1.1 safety valve in the normal production of the valve leakage and overpressure can not be reset after opening.
1.2 to facilitate the technical supervision department in the production of the safety valve for monitoring.
1.3 in the important equipment, processes directly affect the production system of the start and stop, to the enterprise caused economic losses.
1.4 Equipment and devices for the production or storage of contaminants or dangerous gases and liquids.
For safety valves that are discharged to the torch or enclosed system, even if the outlet pipe does not need to be provided with a bypass, a shut-off valve is normally installed on the outlet of the safety valve and sealed to allow the safety valve to be damaged. , Otherwise the entire torch or closed system should be shut down.
2. Safety valve bypass setting
The safety valve bypass setting is not required. The purpose of the safety valve bypass is to allow the safety valve to protect the equipment and the system without downtime to repair the safety valve. Only those important safety valves that require on-line maintenance and no downtime need to be provided with a bypass. It is not necessary to set the bypass if the equipment and system protected by the safety valve can be serviced during the shutdown operation of the safety valve failure. Another effect of the bypass is to open the bypass purge to the torch system when the equipment and the system are purged during open shutdown.
The safety valve bypass is installed on the outside of the shut-off valve of the inlet and outlet valves of the safety valve (between the bypass and the safety valve), which is generally the same as the inlet pipe; it is best to install a pressure gauge on the pipeline near the safety valve, This allows you to monitor system pressure at any time.
Klikkon Industry Co., Ltd is a professional manufacturer of brass machining parts, hot forging parts, brass pipings & fittings, aluminum machining parts.
We have three excellent advantages,
1. We good at producting customized products.We provide one-stop manufacturing services, including: Design,Machining, Inspection, Packaging so as to meet the needs of our customers.
2. We can provide hot forging pressure from 50 tons to 650tons
3. We will free charge to help you to make drawing or design.We will start production after you confirm the finial drawing.Our highly skilled engineers and professionals in the fields of R&D, material knowledge, deforming and machining materials, quality requirements and standards of industrial products.
4. We request a Flexible MOQ, for customer comes from young growing company, we will not request a strict high MOQ. Our vision is to grow up together with our customers.
Klikkon guarantees quality and a corresponding low price, without compromise.
Our highly skilled employees and our high-tech tools, assembly equipment and test control facilities together ensure that "Klikkon quality" delivers you perfection.
Klikkon is your reliable partner for brass products
