译文:
1 泄压阀 泄压阀设置在消防水泵出水管上,平时关闭,在消防给水管网压力超过设定值时自动开启,以防止给水系统因超压而损坏。
消防给水管网的超压主要是由于以下原因:①按消防设计流量选用水泵的流量—扬程曲线属于陡峭型,在小流量运行时(自检或火灾初期)会出现超压;②水泵突然因故(如停电)停转,出水管又未采取相应技术措施,停泵水锤造成超压。
泄压阀设置应注意位置、口径选择、压力设定和相应附件配置等问题。
①泄压阀可设在消防水泵附近或消防水箱附近。自动喷水灭火系统设计规范》GBH84—1985修订本送审稿10.3.3条规定要求:“每组水泵……出水管应设控制阀……,必要时应设泄压阀。”该条文在报批稿中被改为:“……必要时,应采取控制供水泵出口压力的措施。”这些措施即包括泄压阀。
当泄压阀设置在消防水泵出水管上时,可设在止回阀前、后。设在止回阀前能消解水泵小流量运行所造成的超压,而设在止回阀后(沿水流方向)不仅可消解因水泵小流量运行而造成的超压,还可消解由停泵水锤造成的超压,即使消防水泵出水管未采取其他
xx停泵水锤的措施(速闭式止回阀、缓闭式止回阀、缓冲罐等),也不致造成危害和损失。
②泄压阀口径有两种做法,一种是与消防给水总管同径或小一级,另一种是采用DN100或DN150的泄压阀。
从泄压的角度讲,泄压阀的口径越大泄压越快、效果越好。如图1所示,Q为泄流量,泄压阀的口径大,Q值就大,RBC曲线偏向右侧,R曲线与H曲线相交点M也会右移,其压力值随之降低。但从经济角度看,口径越大,泄压阀价格越高,必然增加工程建设费用。因而从实际出发,目前倾向于采用固定口径的
泄压阀,即使泄压时实际压力值会稍大于大口径泄压阀泄压的实际压力值,但综合效果还是可行的。因此,泄压阀口径可作如下规定:若消防给水总管管径D≤150mm,则采用
DN100的泄压阀;若消防给水总管管径D>150mm,则采用DN150的泄压阀。
③泄压阀的压力设定值应高于消防主泵和稳压泵的压力设定值。当有稳压泵时,启动和关闭稳压泵存在两个压力值(指稳压泵运行时的压力值)。稳压泵的停泵水锤压力容易造成泄压阀误开启,因此对于稳高压消防给水系统应有完善可靠的xx停泵水锤的技术措施,并应复
核消防给水管网在水锤产生后的残余压力,若低于泄压阀的压力设定值,才可确保不致误开启。
④泄压阀应设置在与消防给水总管连接的支管上。为方便泄压阀检修及防止控制阀误关闭,在泄压阀前应设信号闸阀或信号蝶阀。为保持泄压阀维修时水流畅通,应设置旁通管。
2 紧急关闭阀
紧急关闭阀平时开启,在管网压力超过压力设定值时自动关闭,以防止消防水泵运行时消防用水进入水箱,同时可防止在消防水泵运行时,生活—消防共用给水系统中生活给水配件因超压而损坏。
我国推荐生活和消防共用的给水系统。这类系统平时启动生活水泵的压力值较低,火灾时启动消防水泵的压力值远高于启动生活水泵时的压力值,而按《建筑设计防火规范》第8.6.3条第四款规定:“发生火灾后,由消防水泵供给的消防用水不应进入消防水箱。”为解决这一问题,应在进入消防水箱的管道上设置紧急关闭阀(如图2)。同时为防止消防水泵启动时生活给水配件超压,应在生活给水总管上设置紧急关闭阀。
紧急关闭阀的问题是压力设定。若压力设定过低,生活水泵启动时紧急关闭阀也会关闭;若压力设定过高,消防水泵启动时紧急关闭阀不关闭。一般,其压力设定值应高于生活水泵零流量时的压力值,低于消防水泵设计流量值时的压力值。同时在给水总管上必须采取可靠的技术措施以防止产生水锤。
3 紧急开启阀 紧急开启阀应用于水喷雾灭火系统,目前尚未在工程中实施。紧急开启阀平时关闭,在管网
压力达到压力设定值时自动开启通水,目的是防止水喷雾灭火系统在消防水泵达到额定转速 前因压力偏低而出现的水喷淋现象。
消防给水管道设置的阀门以常开的为多,而紧急开启阀要求常闭,即在消防水泵启动后达到
额定转速,管网压力达到设计要求压力值时才开启,这就要求阀门的启闭正常、可靠。紧急
开启阀性质与泄压阀相近,都在达到压力值时开启,不同之处在于泄压阀开启后,水流排放或回流至消防水池以泄压;紧急开启阀开启后,水流进入水喷雾灭火系统用于灭火。两者都属于水力控制阀范畴,都设置有用于先导的针阀,而针阀易因杂质堵塞而不能动作;都有用于控制阀瓣动作的隔膜,隔膜为橡胶材质、易老化、磨损。对这两个部件采取的相应措施是
:①在针阀前设置多级过滤器,过滤器滤网孔目逐级缩小,以截留固体颗粒杂质;②橡胶隔膜采用优质产品,并定期检查隔膜和水力控制阀内弹簧的情况。
目前泄压阀、紧急关闭阀和紧急开启阀都作为通用阀门对待,而未列入消防专用阀门范畴,不需通过消防产品质量监督检验测试中心检测。笔者认为这种情况应予改变,泄压阀、紧急
关闭阀和紧急开启阀都只用于消防给水系统,应尽快将其纳入消防专用产品的范畴。
“ Pressure relief valves, emergency shut down valve and emergency valve set to open ”是由提供的国际阀门新闻,译文仅供参考。另外,中国气动阀门网还提供相关产品搜索:、、、、等。
原文:
A pressure relief valve Fire pump pressure relief valve in the
outlet pipe on the set, usually close to the water supply network
in the fire pressure exceeds a set value automatically open to
prevent the water supply system damaged due to excess pressure.
Fire water supply network of the excess pressure was mainly due to
the following reasons: ① the design flow used by the fire pump flow - lift curve is steep
type, running in the low flow (the initial self-test or fire) will
occur over pressure; ② pump suddenly due to it (such as power
failure) stops and the outlet pipe has failed to take appropriate
technical measures, Water hammer caused by overpressure. Relief
valve setting should pay attention to location, caliber choice,
pressure and corresponding accessories set configuration and other
issues. ① pressure relief valve may be located in the vicinity of
the fire pump or fire water tank in the vicinity. Sprinkler system
design "GBH84-1985 amendments required under the provisions of this
manuscript 10.3.3:" Each pump outlet pipe should be located ... ...
... ... control valves, pressure relief valves need to be
established. "This provision in the Draft for Approval was read:
"... ... when necessary, should be taken to control the pump outlet
pressure for the measure." measures that include the pressure
relief valve. When the fire pump pressure relief valve set when the
outlet pipe can be located in the check valve before and after.
Prior to digestion in check valve to run water pumps low flow
caused by the overpressure valve is designed in the post (along
flow direction) by digestion of the pump has not only caused a small traffic
running over pressure, but also stop the pump from the digestion
overpressure caused by water hammer, even though the fire did not
take the other to eliminate water pump outlet pipe Water hammer
measures (speed closed check valve, relief valve closed, the buffer
tank, etc.), it will not cause harm and loss. ② pressure relief
valve bore two approaches, one is with the fire water mains with
diameter or smaller level, the other is based on the pressure
relief valve DN100 or DN150. From the relief perspective, the
greater the pressure relief valve pressure relief aperture the
faster the better. Shown in Figure 1, Q for the vent flow, pressure
relief valve of the caliber, Q value is large, RBC curve skewed to
the right, R curve and the curve of intersection of M H will be
shifted to the right, the pressure value decreases. But from an
economic point of view, the greater the diameter, pressure relief
valves to higher prices, will increase construction costs.
Therefore proceed from reality, the current preference for a fixed
diameter pressure relief valves, pressure relief even when the
actual pressure value is slightly larger than large diameter
pressure relief valve pressure relief of the actual pressure value,
but the combined effect is still feasible. Therefore, the pressure
relief valve diameter can be defined as follows: If the fire water
mains pipe diameter D ≤ 150mm, then use the pressure relief valve
DN100; if the fire water mains pipe diameter D> 150mm, then use
the pressure relief valve DN150. ③ the pressure relief valve
setting should be higher than the main pumps and fire pump pressure
regulator settings. When a regulator pump, pump start and turn off
the regulator, there are two pressure values (defined as the
pressure regulator pump run-time value). Regulators Pump Water
hammer pressure relief valve easily lead to wrong turn, so the
stable high-pressure fire water system should be comprehensive and
reliable Water hammer eliminating the technical measures, and
should review the fire water supply network after the election in
the water hammer residual pressure, if below the pressure relief
valve pressure setting in order to ensure that no mistake to open.
④ pressure relief valve should be set in connection with the fire
water supply mains on the branch. To facilitate maintenance and
prevention of pressure relief valves control valve error closed,
the pressure relief valve should be set prior to signal gate valve
or butterfly valve signal. In order to maintain smooth water flow
pressure relief valve repair should be set to bypass. 2 emergency
shutdown valves Emergency shutdown valve normally open pressure
exceeds the pressure in the pipe network settings automatically
shut down to prevent the fire pump to run water into the tank when
the fire while the fire pump to prevent run-time, live - live fire
shared water supply system for water fittings overpressure damage.
My recommendation shared life and fire water supply system. Such
systems usually start with lower values of life pressure water
pump, fire, fire pump start pressure is lower than the water pump
started life when the pressure value, while the "architectural
design" Fire Safety Code section 8.6.3 Paragraph Four of Article:
"After the fire, the fire water pump fire water supply should not
enter the fire water tank." To solve this problem, should be in the
pipeline into the water tank set on fire emergency shutdown valve
(Figure 2). At the same time to prevent the fire water pump started
life accessories overpressure, water mains should be set in the
life of emergency shut down valve. Emergency shutdown valve problem
is that the pressure setting. If the pressure set too low, pump
life will start when the emergency shutdown valve closed; if the
pressure set too high, the fire pump starts when the emergency
shutdown valve does not close. General, the pressure set value
should be higher than the life of the pressure when the pump flow
value of zero, less than the fire pump design flow rate value of
the pressure values. At the same time in the water mains must be
taken to reliable technical measures to prevent the development of
water hammer. 3 Emergency Open valve Emergency Open valve used in
the water spray system, has yet to be implemented in engineering.
Emergency open valve normally closed, pressure in the pipe network
to automatically open when the pressure setting the water, to
prevent water spraying fire extinguishing system in the fire pump
rated speed antecedent low pressure water spray phenomena arise.
Fire water supply pipeline to set valve to normally open for more
requests and urgent to open the valve normally closed, that the fire pump starts to reach the rated
speed, the pressure pipeline network to meet the design
requirements when the pressure value to open, requiring valve open
and close properly, and reliable. Nature and emergency pressure
relief valve to open the valve similar to the pressure value in
turn, is the difference between the pressure relief valve opens,
water discharge or return to the fire water to relief; emergency
open valve is opened, the water flow into the water spray fire
extinguishing system for fire fighting. Both areas are hydraulic
control valve, all set up for the pilot of the needle valve, while
the needle can not be easily blocked by impurities in action; are
used to control the movement of the diaphragm flap valve, for the
rubber diaphragm material, easy to aging, wear and tear. These two
parts to corresponding measures: ① in the pre-set multi-needle
filter, filter strainer head progressively narrow hole to retain
solid particles and impurities; ② rubber diaphragm with
high-quality products, and regularly check the diaphragm and
hydraulic control valve spring situation. Current pressure relief
valves, emergency shut down valve and emergency valve open valves
are treated as a universal and not in areas of fire control valve
without fire products by Quality Supervision and Testing Center
test. I believe that this situation should change, pressure relief
valves, emergency shut down valve and open the valve only for
emergency fire water supply system, should be included in the scope
of fire control products.
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