Diesel Technology Fittings/ Hoses

What is the most common repair on vehicles? Leaks!

Fittings/ Hoses: Are used in many applications in the Diesel industry. They are used as part of of system to transport fluids from one location to another. In this industry a diesel technician must be able to identify fittings/ hoses, which will allow them to perform service repairs.

What types of fluids are used in the Diesel Industry? Engine oil Transmission oil Temps up to 220 deg. F Pressures up to 2000 psi Temps up to 300 deg. F Pressures up to 200 psi Coolant Hydraulic oil Temps up to 250 deg. F Pressures up to 20 psi Pressures up to 6000 psi

Fittings/ Hoses: A basic understanding of fittings/ hoses is needed for today’s diesel technician. Accidents and injury occur – if the technician does not understand basic fittings/ Hoses.

Hoses: There are three different methods employed to transport fluids within a system. Hose. Tubing. Pipe.

Hose: Hose: is a flexible method of directing fluids from one location to another. The hose is matched to the fluid being transported (coolant, fuel, oil, temp, pressure). Hose: is measured by its inside diameter. Hose information is printed on each hose on the “lay-line”. It is up to the service technician to use the correct hose for the specific application.

Hose Not as strong as tubing Required on mobile vehicles due to the movement of components Excellent vibration damping characteristics.

Tubing: Tubing: is a Semi-flexible method of directing fluids from one location to another. The tube is used in locations in there is little or no movement between components. Tubing: is measured by its outside diameter. Tubing is used in a wide variety of applications: fuel systems (high pressure), air systems (medium pressure), and low pressure (cooling systems. It is up to the service technician to use the correct hose for the specific application.

Tubing: Tubing is made out of four common materials: Copper: (low pressure application). Steel: (high pressure application). Nylon braided: (medium pressure). Stainless Steel: (high pressure, alternative fuels). Never use copper tubing for high pressure applications.

Pipe: Pipe: is a Rigid method of directing fluids from one location to another. Pipe: is measured by its inside diameter. This measurement is a relative size, because pipe is available with different wall thickness (as the wall thickness increases the inside diameter decreases).

Pipe: Pipe: is available in three different schedules (wall thickness): Schedule 40: (common pipe). Schedule 80: Schedule 160: When replacing pipe replace the damaged pipe with the correct schedule pipe.

Pipe: Pipe: is made out of two common materials: Brass: Steel: Never use Pipe for high pressure applications.

Fittings: There are four basic classifications of fittings studied in this class: Pipe. SAE 45. Inverted. Compression.

Pipe:

Pipe: Seals by a thread interference fit (male-female) Male and Female tapered threads.

SAE 45:

SAE 45: Seals by trapping a 45° surface between two sealing surfaces. Connects: Pipe to Tube. Tube to Tube.

Inverted Flare:

Inverted Flare: Seals by trapping a 45° surface between two sealing surfaces. Is the opposite of SAE 45°. Connects: Pipe to Tube. Tube to Tube.

Compression:

Compression: Seals by distorting a sleeve on a tube, this distortion seals the fitting.. Connects: Pipe to Tube. Tube to Tube.

Identify How the following Fittings seal!

Identify Classification: Is for you to be able to identify basic hydraulic fittings. This is an individual/ group study time. Look at each fitting and identify how it seals. That will identify the classification.

Identify Description: Look at the fitting: Pipe to Tube = Connector. Tube to Tube = Union. Pipe to Pipe = Coupling, Nipple, Bushing. Is the fitting changing direction: 90° elbow, or a 45° elbow.

Identify Sizes: Look at the ends of the fitting: Identify the correct size: 1/8 >>>>> P or T. ¼ >>>>> P or T. 3/8 >>>>> P or T. ½ >>>>> P or T.

Any Questions ??

Study Time !!

The END !!