阀体上开孔
Wall Tapping

允许开孔的没有凸缘的阀体上的最大管道尺寸
MAXIMUM PIPE SIZE THAT MAY BE TAPPED IN VALVE WALL WITHOUT ANY BOSSES

轮箍位置上的开孔
Tapping of Boss Locations

　　所有美国尼伯科阀门都可以进行开孔，用于排泄和特种攻丝。轮箍位置，符号和开孔程序应该遵守MSS旁路和排泄连接标准SP 45。如果需要在标准轮箍位置以外的地方进行开孔，则必须提供清楚的示意图，显示阀门上的准确位置。美国尼伯科将审查开孔要求，如果要求能够满足，将加以指导。所有开孔都将堵塞，不需要额外费用。
　　All NIBCO iron valves are available with tapping for drain and special tapping. Boss locations and symbols and tapping procedures are in accordance with MSS By-Pass and Drain Connection Standard SP 45. When tappings are needed at any other than the standard boss locations, a sketch must be provided clearly showing the exact location on the valve. NIBCO will review the request and advise if request can be met. All tappings are plugged at no extra charge.

　　如果轮箍需要开孔，开孔的标准尺寸则按照下列MSS规范SP 45，表1的表格。
　　When bosses are ordered tapped, the standard size of tapping is in accordance with the following table taken from MSS Specification SP 45, table 1.

旁路
By-Passes

　　在打开住阀门之前，可以采用旁路来平衡进口和出口压力，使得阀门更加容易操作。可以在所有的美国尼伯科阀门上设置旁路，但须符合MSS旁路和排泄连接标准Sp 45。用于标准铸铁阀门上的旁路阀门是一个截止阀。在UL认证和FM认证的铸铁阀门上，旁路阀门应该是一个UL-FMRC认证的青铜闸阀。请在型号上加上（Z）进行规定，例如：F-00-Z。
　　A By-Pass can be used to equalize pressure at inlet and outlet before opening main valve; facilitating easy valve operation. The built-up type By-Pass is available on all NIBCO iron valves and is attached in accordance with MSS By-Pass and Drain Connection Standard SP 45. The By-Pass valve used on standard iron valves is a globe valve. On Underwriter's & Factory Mutual iron valves, the By-Pass valve is a UL-FMRC bronze gate valve. Specify by adding a (Z) to Figure Number, i.e. F-000-Z.

　　用在美国尼伯科铸铁闸阀、截止阀、角阀和常规旋启式止回阀上的旁路阀通径，符合适用于蒸汽应用的MSS规范SP 45表II系列A。UL-FM认证的阀门则符合MSS规范SP 45表II系列B。
　　Sizes of by-pass valves on NIBCO Iron Gate, Globe, Angle and regular Swing Check valves conform to MSS Specification SP 45 Table ll Series A for steam service. UL-FM approved valves conform to MSS Specification SP 45 Table ll Series B.