Bypass valve is mounted above positive displacement motor and used to connect internal drill pipe chamber with annulus during trips. Use of the valve reduces hydrodynamic effect on bottom while drill sting trip and protects PDM from no-load rotation. While pulling out, PDM in conjunction with the valve excludes uncontrolled mud spilling.

The bypass valves are suitable for the mud density of up to 2 g/cm³ at the bottomhole, temperature of not exceeding 130 °C, the content of oil products of less than 10 %, sand of less than 1%.

Specifications	Designations
	KP-76	KP-88	KP-95 KP-106	KP-120	KP-127	KP-165	KP-178	KP-195	KP-210	KP-240
Outer diameter, mm	76	88	105	120	127	165	178	195	210	240
Diameter of flow area, mm	20	20	28	28	28	45	50	50	50	55
Total length, mm	436	436	595 584	435	605	554	567	567	567	587
Case length, mm	360	360	495	333	505	440	440	440	440	460
Connecting thread, top (box)	З-66	З-66	З-86	З-102	3-102	З-133	З-147	З-147	З-152	3-171
Connecting thread, bottom (pin)	З-66	З-66	З-86	З-102	3-102	З-133	З-147	З-147	З-152	3-171
Valve closing pressure, kg/cm2	1,4-2,1	1,4-2,1	2-3	2-3	2-3	2,4-3,1	2,3-3,0	2,3-3,0	2,3-3,0	2,8-3,7
Mud flow rate, l/s, not more than	10	10	25	25	25	40	50	50	50	55
Weight, kg	10	14	26	24	41	55	66	81	99	130

 

Sand content in the mud shouldn't be more than 1%.
Mud density shouldn't be more than 2g/cm³.