Module 3 Hydraulic components Nonreturn valves Prepared by Samir Hamasha Warm Up Module 3 Non return valves Module Objectives After the completion of this module the student should be able to ID: 368280
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Basic Hydraulics and Pneumatics
Module 3: Hydraulic components(Non-return valves)
Prepared by : Samir HamashaSlide2
Warm UpSlide3
Module 3: Non return valves
Module Objectives After the completion of this module the student should be able to:
Identify the types of non return valves.
Identify the symbols of non return valves.
Identify the functions of non return valves.
Draw the hydraulic circuit diagram.
Simulate the circuit diagram using
FluidSIM
software.
Design and construct the task circuit practically and check its operation. Slide4
Module 3: Non return valves
Non - return valves:
Non-return valves are used to block the flow in one direction and allow free flow in the other direction.
Shut off valve
The shutoff valve is a manually opened or closed valve.
This valve is shown in Fig. 3.1.a,
The I.S.O symbol of the shut off valve
is shown in Figure 3.1.b and it has two ports (A) and (B
(a)
(b)
Fig.3.1:(a) Shut off valve
(b) ISO symbol of shut of valveSlide5
Module 3: Non return valves
1-2 Check valve (Non-return valve) It used to allow the flow only in one direction; which means that the flow in the opposite direction will be completely blocked.
The valve is shown in Fig. 3.2.a,
it has (2 ports A and B )
The flow is allowed from (A) to (B)
The flow is blocked from (B) to (A)
The ISO symbol of this valve is shown in Fig.3.2.a as non spring check valve and Fig.3.2.b spring loaded check valve
Fig.3.2:
(a) Check valve
(b) ISO symbol of check valve (non- spring)
(c): ISO symbol of check valve (spring
loaded
(c)
(b)
(a) Slide6
Module 3: Non return valves
Pilot
Check valve
The function of the pilot check valve
is to allow the flow only in one direction from port (A) to port (B), and also allows the flow in the opposite direction only when the port (x) has a pilot signal.
These valves have a pilot connection which can open the valve in the blocked direction, when a pilot signal is applied.
The valve is shown in Fig. 3.3.a, it has (3 ports A , B and X )
(B): port for output pressure(A): port for input pressure
(X): port for pilot pressure
The ISO symbol of this valve is shown in Fig.3.3.b
(a)
(b)
(a)
Fig.3.3:
(a) Pilot check valve
(b) ISO symbol of Pilot
check valveSlide7
Practical Task I
2.1 Conveyor tensioning device Exercise description:
Parts are fed through a drying oven on a steel chain conveyor belt. It must be possible to correct the tracking of the belt by means of a tensioning device to ensure that the belt does not run off its rollers. This device consists of a steel roller fixed at one end and movable at the other by means of a double-acting cylinder. Hydraulic power must be available continuously.
A piloted non-return valve is used to prevent creeping of the piston rod of the positioning cylinder as a result of oil leakage losses in the directional control valve. Slide8
Practical Task I
2.2 Procedures of solution
Draw the hydraulic circuit diagram for the task on the sheet given to you by your instructor.
Note :
You can work in group of two studentsSlide9
Practical Task I
2.2 Procedures of solution
Hydraulic Circuit Simulation
In group of two students using the Fluid SIM software on the lab computer, draw and simulate the final circuit as shown .
Building the Hydraulic Circuit on the lab workstations :
work in a group of 4 students to assemble the circuit practically and check its operation.
Write down your observationsSlide10
3 Practical Task II
3.1 Calendar feeding device Exercise description:
In this exercise the student will be familiarized with the application of a non return valve
Rolls of paper are lifted into a calendar by a lifting device. The lifting device is driven by a plunger cylinder (single acting
cylinder). When the hydraulic power pack is switched on, the pump output flows directly to the cylinder. A shut off
valve, which is closed in its normal position, is fitted in a branch line leading to the tank. A non return valve is used to
ensure that the pump is protected against the oil back pressure. A pressure relief valve is fitted upstream of the non
return valve to safeguard the pump against excessive pressures
.Note
You can Use a double acting cylinder as a single acting cylinder by connecting return stroke port to the tank.Slide11
Practical Task II
3.1 Calendar feeding deviceProcedures of solution
Draw the hydraulic circuit diagram for the task on the sheet given to you by your instructor.
Note :
You can work in group of two studentsSlide12
Practical Task II
2.2 Procedures of solution
Hydraulic Circuit Simulation
In group of two students using the Fluid SIM software on the lab computer, draw and simulate the final circuit as shown .
Building the Hydraulic Circuit on the lab workstations :
work in a group of 4 students to assemble the circuit practically and check its operation.
Write down your observationsSlide13
Class Activity
1- Draw the I.S.O. symbol of shut off valve.............................................................................................................................................................................................................
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2- What is the function of pilot check valve?
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Draw the I.S.O. symbol of pilot check valve.
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4- Draw the I.S.O. symbol of a 4/3 way valve, lever, spring return.
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6- Draw the I.S.O. symbol of a double acting cylinder.........................................................................................................................................................................................................................................................................................................................................................................................................................