Flat gate valve is widely used in transportation pipelines such as natural gas, petroleum, chemical industry, tap water pipeline, urban pipeline and gas pipeline, vent system and natural gas storage equipment as opening and closing equipment. Z43 single gate flat gate valve with diversion hole is mainly used in long-distance natural gas transportation and purification pipelines.

平板閘閥的長處

Advantages of flat gate valve

流阻小，不縮口的其流阻與短只管的流阻相仿。帶導(dǎo)流孔的平板閘閥安裝在管路上還可直接用清管器進行清管。因為閘板是在兩閥座面上滑動，因此平板閘閥液能合用于帶懸浮顆粒的介質(zhì)、平板閘閥的密封面實際上是自動定位的。閥座密封面不會遭到閥體熱變形的損壞。

The flow resistance is small, and the flow resistance without necking is similar to that of a short tube. The flat gate valve with diversion hole is installed on the pipeline and can also be pigged directly with a pig. Because the gate valve slides on the two seat surfaces, the liquid of the flat gate valve can be used for the medium with suspended particles, and the sealing surface of the flat gate valve is actually positioned automatically. The sealing surface of the valve seat will not be damaged by the thermal deformation of the valve body.

并且即使閥門在冷狀態(tài)下封閉，閥桿的熱伸長也不會使密封面遭到過載。當(dāng)閥門封閉時，無導(dǎo)流孔的平板閘閥亦不需求閘板的封閉方位有較高的精度，因此電動平板閥可用行程來控制啟閉方位。

And even if the valve is closed in the cold state, the thermal extension of the valve stem will not overload the sealing surface. When the valve is closed, the flat gate valve without diversion hole does not require high precision in the closing direction of the ram, so the electric flat valve can control the opening and closing direction by stroke.

平板閘閥的缺點

Disadvantages of flat gate valve

當(dāng)介質(zhì)壓力低時，金屬密封面的密封力缺少以抵達(dá)滿足的密封。相反當(dāng)介質(zhì)壓力高時，假定密封面不需要系統(tǒng)介質(zhì)或外來介質(zhì)潤滑時，常常啟閉就可能使密封面磨損過大。另一個缺點是，在圓形流道上橫向運動的圓形閘板只有當(dāng)它處在閥門關(guān)方位的50%時，這種閥門對流量的控制才較靈敏。并且，閘板在切斷高速和高密度介質(zhì)流時，會發(fā)作劇烈振動。假定將閥座做成V形通口并和閘板做緊密的導(dǎo)向，則它也可起到節(jié)流的作用。

When the medium pressure is low, the sealing force of the metal sealing surface is lack to meet the sealing requirements. On the contrary, when the medium pressure is high, assuming that the sealing surface does not need system medium or external medium lubrication, the frequent opening and closing may cause excessive wear of the sealing surface. Another disadvantage is that the circular gate moving laterally on the circular flow channel is more sensitive to flow control only when it is 50% of the valve closing position. Moreover, the RAM will vibrate violently when cutting off the high-speed and high-density medium flow. Assuming that the valve seat is made into a V-shaped port and closely guided with the gate, it can also play the role of throttling.

平板閘閥選用準(zhǔn)則

Selection criteria of flat gate valve

1.石油、天然氣的運送管線，選用單閘板或雙閘板的平板閘閥。如需清掃管線的，選用單閘板或雙閘板帶導(dǎo)流孔的明桿平板閘閥。

1. For oil and natural gas transportation pipelines, single gate valve or double gate valve shall be selected. If the pipeline needs to be cleaned, the rising stem flat gate valve with single ram or double ram and guide hole shall be selected.

2.成品油的運送管線和貯存設(shè)備，選用無導(dǎo)流孔的單閘板或雙閘板的平板閘閥。

2. For the transportation pipeline and storage equipment of product oil, single gate valve or double gate valve without diversion hole shall be selected.

3.石油、天然氣的發(fā)掘井口設(shè)備，選用暗桿起浮閥座帶導(dǎo)流孔的單閘板或雙閘板的平板閘閥，大多為API6A標(biāo)準(zhǔn)，壓力等級為API2000、API3000、API5000、API10000、API15000、API20000。

3. For oil and natural gas exploration wellhead equipment, single or double ram flat gate valves with Non rising stem valve seat and guide hole are selected, most of which are api6a standard, and the pressure grades are api2000, api3000, api5000, api10000, api15000 and api20000.

4.帶有懸浮顆粒介質(zhì)的管道，選用刀型平板閘閥。

4. Knife type flat gate valve shall be selected for the pipeline with suspended particle medium.

5.城市煤氣運送管線，選用單閘板或雙閘板軟密封明桿平板閘閥。

5. Single or double ram soft sealing rising stem flat gate valve shall be selected for urban gas transportation pipeline.

6.城市自來水工程，選用單閘板或雙閘板無導(dǎo)流孔明桿平板閘閥

6. Single gate valve or double gate valve with rising stem without diversion hole shall be selected for urban tap water project