Discussion on the use of signal valves for fire hydrant control valves in high-rise buildings

Discussion on the use of signal valves for fire hydrant control valves in high-rise buildings

Abstract: The suggestion high-rise building fire hydrant control valve using signal valve discussion
Key words: high-rise building fire hydrant control valve signal valve
According to the provisions of “Code for Fire Prevention Design of high-rise Civil Buildings”, in the indoor fire hydrant system, the water supply pipeline should be divided into several ** sections, and the valve should have obvious open and close signs. This is so that the number of hydrant standpipes is not less than one when the pipe is being serviced.
With the development of modern architecture, the building of various pipelines for beautiful demand should be hidden as far as possible to decorate, therefore, hydrant pipes in the ceiling, tube well, is widespread, but this is a problem, namely the control valve of the open fire hydrant pipe can not get monitoring, to cause fire hydrant can be normal use. Here are some examples:
The project of “State Grid Control Center of Ministry of Electric Power” covers a construction area of more than 50,000 square meters, with three underground floors and 27 floors above ground. The building height is over 110 meters. It is a comprehensive intelligent building integrating production command and dispatching, office and conference functions, and its high degree of automation is rare in China. In the design of the automatic wine spraying system, I used signal valves in front of all water flow indicators, so the status of the system can be displayed in the fire control center, and problems can be found at a clear sight. In addition, the control of the water level of life and fire fighting, and the start and stop of the fire pump are also reasonably monitored. Only the control valve of the fire hydrant system in accordance with the specification of the ordinary valve, it has obvious signs of opening and closing, but can not be shown in the fire control center, in addition, these valves are located in the tube well and ceiling for aesthetic needs, the quality of the current workers can not ensure the reliability of the system. In the fire protection system in the process of acceptance, although the leadership of the ministry project headquarters, construction units and design units are very seriously, has made the deployment and the early rectification, well rehearsed, but in the process of fire department official actual acceptance, but there is a problem, there is a fire hydrant fire hydrant on the standpipe anyway also can’t let out of the water, and the other four are normal, We can’t find a problem at the fire control center. After inspection, it was found that the control valves at both ends of the riser were closed because of maintenance, and the workers did not open the valves after maintenance, causing the fire hydrant not to water.
I think, in the case that everyone attaches great importance to, still appear this kind of problem, and usually in the case of easy paralysis more do not know what kind of problem will appear. This is related to whether the fire hydrant system is the key to the rational use of problems, and avoid this situation appear * * reliable way is to fire hydrant system control valves are set into the signal valve, and valve open to display in the center of the fire control, so that the management personnel inspection, although the cost has increased, however, The ratio of investment to the whole fire hydrant system is still very small, and it can make the whole fire hydrant system safety ** improvement, which I think is worth the investment.
Control valve according to the classification of structural features (1) through single-seat control valve: the valve * * widely used, has a leak some  allowable differential pressure some  complex flow and the characteristics of simple structure, so is suitable for the strict leakage, small working pressure difference of clean medium, but small specifications of the valve nominal size (DN < 20 mm) can also be used for differential pressure larger occasions. In application, we should pay attention to check the allowable pressure difference to prevent the valve from closing undead.
(2) straight through two-seat control valve: in contrast to the straight through single-seat control valve, it has the characteristics of large leakage and large allowable pressure difference, so it is suitable for clean media occasions with lax leakage requirements and large working pressure difference. Attention should be paid to whether the leakage amount of the valve meets the process control requirements when selecting the valve.
(3) Sleeve valve: sleeve valve is divided into single seal and double seal two structures, the former is similar to a single seat valve, suitable for single seat valve occasions. The latter is similar to a two-seat valve, suitable for two-seat valve occasions. Sleeve valve also has the characteristics of good stability, convenient loading and unloading, but the price is 50% ~ 200% higher than the single seat valve, double seat valve, also need special winding gasket. Sleeve valve is the most inferior to the single – seat valve, double – seat valve application of the valve.
(4) the Angle valve, throttle form is equivalent to a single seat valve, but the body flow is simple, applicable to leak requires some  clean medium occasions and requirements of differential pressure is the rectangular pipe.
(5) three-way valve: it has 3 channels, can replace the two straight single-seat valve, used for shunt and confluence and two-phase flow, temperature difference is not more than 150 ℃. When DN≤80 mm, confluence valve can be used for shunt occasions.
(6) Diaphragm valve: simple flow path, diaphragm has certain corrosion resistance performance, suitable for unclean medium, weak corrosion medium two cut off occasions.
Butterfly valve (7) : it is equivalent to apply section for the body, and the body is equal to the seat again, so the “self-cleaning” performance is good, some  volume weight. Suitable for unclean medium and large diameter, large flow, large pressure difference. When Dn > 300 mm, it is usually completed by butterfly valve.
(8) Ball valve: “O” type ball valve when fully open for the open valve, “self-cleaning” performance is better, suitable for especially clean, fiber medium two cutting occasions. “V” BALL valve has approximately equal percentage adjustment characteristics, suitable for unclean, containing fiber media, adjustable relatively large control occasions. Ball valves are more expensive.
(9) Eccentric rotary valve: the valve between the butterfly valve and ball valve, “self-cleaning” performance is good, good regulating performance, can be cut off, so it is suitable for unclean medium, leakage requirements of small regulating occasions, but the price of the valve is more expensive.
The first 6 of these 9 products are direct stroke control valves, and the last 3 are angular stroke control valves. As the application of the control valve, it is necessary to make clear their characteristics and matters needing attention. All kinds of variant products, improved products are evolved in these 9 categories of products, it is easy to understand the 9 categories of products to master the application of other products.