NPT Pipe Plug Fitting Internal Hex Thread Socket

2、Automobile engine & NPT Pipe Plug Fitting Internal Hex Thread Socket

On an automobile engine, the NPT Pipe Plug Fitting Internal Hex Thread Socket is a seemingly insignificant component that, without it, the engine would leak oil and water. It is the "plug" for those holes cast or machined on the engine cylinder block and cylinder head.

【1】Where on the engine will it be used?

（1）Cylinder block oil passage: The casting process holes of the engine's main oil passage. After the crankshaft hole is machined, the side holes should be sealed with NPT Pipe Plug Fitting Internal Hex Thread Socket to prevent the oil from spraying out completely.

（2）Cylinder block water passage: The process holes for the coolant channels. After the water jacket is machined, some side or end openings need to be sealed.

（3）Cylinder head: The casting sand core holes on the cylinder head need to be sealed to prevent coolant from leaking.

（4）Pump housing: The casting process holes, or the drain ports, need to be blocked.

（5）Oil cooler base: Some unused oil ports.

【2】Why are NPT hexagonal plugs particularly favored in engine applications?

（1）The conical thread seal is reliable: The internal temperature of the engine fluctuates greatly (from -30°C to over 120°C), and there is also vibration. The NPT conical thread combined with sealing adhesive is more heat-resistant and vibration-resistant.

（2）Hexagon head facilitates installation: These holes on the engine are often on the sides or in grooves. Open-end wrenches or sockets may not be able to reach them, but hexagon head wrenches are easier to use.

（3）Keep it hidden and do not interfere: After the NPT Pipe Plug Fitting Internal Hex Thread Socket is tightened, the top can be flush with the surface of the cylinder block, and it will not affect the assembly of other parts.

【3】Common scenarios during maintenance

（1）During the modification process, seal off the unused interfaces: for instance, if the EGR system is removed, the interface on the intake pipe needs to be blocked with a plug.

（2）Replacing the heating plug: In older diesel engine cylinder heads, there are electric heating plugs. If they are no longer needed, simply cover the holes with plugs.

（3）Oil pressure sensor interface: If the sensor is removed, immediately screw on the NPT Pipe Plug Fitting Internal Hex Thread Socket; otherwise, it will spray oil when the engine starts.