(A) direction and position
Many valves have directional, such as cut-off valves, throttle valves, pressure relief valves, check valves, etc., if installed reverse, it will affect the use of life and efficiency (such as throttle), or simply does not work (such as Pressure relief valve), and even cause danger (such as check valve). General valve, the direction of the valve body signs; if not, should be based on the valve works, the correct identification. (The shape of the decision), open the effort (due to media pressure up), after the closure of the media is not pressure packing, easy to repair, the valve is not symmetrical, the fluid to let it from the bottom up through the valve port, so that the fluid resistance is small (determined by the shape) , This is why the cut-off valve can not be the truth. Other valves also have their own characteristics.
Valve installation location, must be easy to operate, even if the installation is temporarily difficult, but also for the operator's long-term work for the sake of. The best valve hand wheel and chest to get together (generally from the operating floor 1.2 meters), so that the opening and closing valves more energy. Floor valve hand wheel to be up, do not tilt, so as to avoid awkward operation. Rely on the wall by the equipment of the valve, but also set aside the operator room. To avoid day-to-day operation, especially acid, toxic media, etc., otherwise very safe. Do not flip the door (that is, hand wheel down), otherwise it will make the media long-term retention in the bonnet space, easy to corrosion stem, but also for some of the requirements of the taboo. At the same time to replace the filler very inconvenient. Do not install the gate valve, or because of the wet and corrosion of the exposed stem. Lift check valve, the installation to ensure that the valve flap vertical, so that flexible lift. Swing check valve, the installation to ensure that the pin level, in order to spin open flexible. The pressure relief valve should be installed upright on the horizontal pipe and should not be tilted in all directions.
(B) construction work
Installation and construction must be careful not to impact the brittle material produced by the valve.
Before installation, the valve should be a check, check the specifications model, identify whether the damage, especially for the stem. But also to turn a few times to see if the skew, because the transport process, the most likely to hit the broken stem. Also remove the debris from the valve.
When the valve lifts, the rope is not tied to the hand wheel or stem, so as not to damage these parts, should be tied to the flange.
For the pipeline connected to the pipeline, be sure to clean. You can use compressed air to blow iron oxide chips, mud, welding slag and other debris. These debris, not only easy to scratch the sealing surface of the valve, which large particles debris (such as welding slag), but also to plug a small valve, to failure. When installing the screw valve, seal the packing (linen plus aluminum or polytetrafluoroethylene raw tape), the pipe thread, do not get the valve, so as not to accumulate the valve, affecting the media circulation.
When installing the flange valve, pay attention to the symmetrical even tightening bolts. Valve flanges and pipe flanges must be parallel, the gap is reasonable, so as to avoid excessive pressure on the valve, or even cracking. For brittle materials and high strength of the valve, with particular attention. To be welded with the pipe valve, should first spot welding, and then the closure of the full open, and then die.
(C) protection measures
Some valves must also have external protection, which is insulation and cold. Insulation layer is sometimes added to the hot steam line. What kind of valve should be insulated or cold, according to production requirements.
In principle, where the valve medium to reduce the temperature too much, will affect the production efficiency or froze the valve, you need insulation, and even mixed heat; where the valve exposed, adverse production or cause frost and other undesirable phenomena, you need cold. Insulation materials are asbestos, slag cotton, glass wool, perlite, diatomaceous earth, vermiculite, etc .; cold materials are cork, perlite, foam, plastic and so on.
(D) bypass and instrumentation
Some valves, in addition to the necessary protective facilities, but also bypass and instrumentation. A bypass is installed. Easy to trap traps. Other valves, also installed by the bypass. Whether to install the bypass, depending on the condition of the valve, the importance and the production requirements.