TSM 363 Fluid Power Systems. Hydraulic Hoses & Pipeline. Conductors for Fluid Delivery. It’s common for using hoses and tubes on ORE as fluid conductors. Hoses are flexible and tubes are rigid conductors. There are three criteria in selecting the conductors.
Hydraulic Hoses & Pipeline
It’s common for using hoses and tubes on ORE as
Hoses are flexible and tubes are rigid conductors.
There are three criteria in selecting the conductors.
Rule of thumb: use flexible hoses whenever you can.
Inner tube: Oil resistant thermoplasticflexible tube Direct contact with the hot hydraulic oils
Reinforcement layer:making hoses stronger
wire- or fabric-reinforced
outer layer: endure the useful life
weather, oil, or abrasion-resistant.
It is a must to use some types of hose connectors(often calledfittings), either reusable or no-reusable, for connecting hoses.
SF: safety factor. It is recommended to take SF=8 for pressures below 1000 psi SF=6 for pressures between 1000~2500 psi SF=4 for pressures above 2500 psiPressure Rating of Conductors
Two Pressure Ratings: Burst Pressure (BP) – the fluid pressure will cause the pipe to burst.
Working Pressure (WP) – the maximum safe operating fluid pressure
The recommended fluids velocity for different conductors:
Pump inlet line: 4 ft/sec
Pressured lines: 0-500 psi 15 ft/sec
500-3000 psi 20 ft/sec
over 3000 psi 25 ft/sec
Return line: 15 ft/secSizing the Conductor
The size of the hose/tube in a fluid power system is
determined based on the velocity of the fluids moving
(ft/sec)Exercise: Select Conductor Uses Nomograph
The Size of the hose is determined based on the velocity of the fluids moving in it.
The operationTemperature rangeof a hose is determined by the materials in the hose is made of.
A good Applicationplanis to route the high-pressure lines parallel to machine contours whenever possible.
It is mandatory to check the compatibility of hose fabricatingMaterialsbeing used with the fluids used in the system.
Hose rated working Pressure needs to be chosen correctly forsafe operation.
Use of proper fittings on both Endsof the hose segments.
The Deliverability of the selected components in a timely manner.