Application: Safety sub is used to connect the upper top drive kelly valve with lower drill pipe.

Design: The joint is an integral structure processed with high-quality alloy structure, and will be subjected to a special heat treatment process to achieve the expected hardness, strength and impact resistance.

Type	ID.mm(inch)	OD.mm(inch)	Connection API
DQJT187B	54(2 1/8)	187(7 23/64)	6 5/8REG BOX x NC38 PIN
DQJT187B	69.85(2 3/4)	187(7 23/64)	6 5/8REG BOX x NC50 PIN
DQJT187A	76.2(3)	187(7 23/64)	6 5/8REG BOX x 5 1/2FH PIN
DQJT197B	54(2 1/8)	197(7 3/4)	6 5/8REG BOX x NC38 PIN
DQJT197B	69.85(2 3/4)	197(7 3/4)	6 5/8REG BOX x NC50 PIN
DQJT197A	76.2(3)	197(7 3/4)	6 5/8REG BOX x 5 1/2FH PIN
DQJT216B	54(2 1/8)	216(8 1/2)	7 5/8REG BOX x NC38 PIN
DQJT216B	69.85(2 3/4)	216(8 1/2)	7 5/8REG BOX x NC50 PIN
DQJT216B	76.2(3)	216(8 1/2)	7 5/8REG BOX x 5 1/2FH PIN

Ordering instruction:

Any special requirement on thread type or temperature, please specify before order.