浮阀通常安装在钻具接头的标准孔中，用以控制钻杆底部的液流。在停泵换钻杆时，浮阀还能防止切屑从钻头喷嘴中返回。

Type	Dia. of Valve Assembly	Length Of Valve Assembly	Dia. Of Float Recess	Sub Box		Other Popular Connections
	mm(inch)	mm(inch)	mm(inch)	Connection	Depth Of Recess	Connection	Depth Of Recess
				API	mm(inch)	API	mm(inch)
1R	42.1(1-21/32)	149.2(5-7/8)	42.9(1-11/16)	2-3/8Reg.	231.8(9-1/8)	NC23	231.8(9-1/8)
2F-3R	61.1(2-13/32)	165.1(6-1/2)	61.9(2-7/16)	3-1/2Reg.	266.7(10-1/2)	NC31	260.35(10-1/4)
3-1/2 F	79.4(3-1/8)	254(10)	80.2(3-5/32)			NC38	362.0(14-1/4)
4R	88.1(3-15/32)	211.1(8-5/16)	88.9(3-1/2)	4-1/2Reg.	325.4(12-13/16)	NC44	331.8(13-1/16)
5R	98.4(3-7/8)	247..7(9-3/4)	99.2(3-29/32)	5-1/2Reg.	374.7(14-3/4)	NC50	368.3(14-1/2)
5F-6R	121.4(4-25/32)	298.5(11-3/4)	122.2(4-13/16)	6-5/8Reg..	431(17)	5-1/2IF	431.8(17)
When ordering or requesting quotation, if size out of above specification, pls. specify clearly.