• 1/4 BSPP Double Acting Pilot Check Valve
    Regular price £21.17
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    1/4 BSPP Double Acting Pilot Check Valve

    Key Features

    • Type: straight adaptor (BSP threading per title)
    • Threads: 1/4 thread
    • Standard: BSPP parallel per ISO 228 unless otherwise specified
    • Material: plated carbon steel for hydraulic service
    • Use: join hoses; valves; pipe runs or adapt port sizes
    Regular price £21.17
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  • DIN 3/8 BSPP Double Acting Pilot Check Valve - Pipe12
    Regular price £22.07
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    DIN 3/8 BSPP Double Acting Pilot Check Valve - Pipe12

    Key Features

    • Type: straight adaptor (BSP threading per title)
    • Threads: 3/8 thread
    • Standard: BSPP parallel per ISO 228 unless otherwise specified
    • Material: plated carbon steel for hydraulic service
    • Use: join hoses; valves; pipe runs or adapt port sizes
    Regular price £22.07
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery
  • Out of Stock
    Dual Pilot Operated Check Valve 1/2"BSP In Line - 35Lpm - Approved Hydraulics Limited
    Regular price £75.16
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    Dual Pilot Operated Check Valve 1/2"BSP In Line - 35Lpm

    Key Features

    • Type: double pilot operated check valve inline
    • Port size: 1/2' bsp
    • Rated flow: 35 l/min
    • Typical max pressure: up to 350 bar
    • Function: locks actuator both directions ; opens with pilot pressure
    Regular price £75.16
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  • Dual Pilot Operated Check Valve 1/4"BSP In Line - 20Lpm - Approved Hydraulics Limited
    Regular price £48.17
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    Dual Pilot Operated Check Valve 1/4"BSP In Line - 20Lpm

    Key Features

    • Type: double pilot operated check valve inline
    • Port size: 1/4' bsp
    • Function: locks cylinder in both directions until pilot pressure applied
    • Typical max pressure: up to 300 to 350 bar
    • Typical cracking: 0.5 bar check with pilot release
    Regular price £48.17
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  • Adam Hindle

    Sales Director

    I began my engineering career at Stockport College in around 2005, first completing a National Diploma in Electrical Engineering, followed by a Higher National Diploma in Mechanical Engineering. I then progressed to the University of Salford, where I earned a BEng (Hons) degree in Mechanical Engineering.

    After graduating, I started my professional career with Approved Hydraulics. I initially gained a combination of hands-on workshop experience and telephone-based sales experience. In later years, I moved into a full-time sales role and led the new crane and excavator attachments department that the company had recently established.

  • Out of Stock
    Hydra Part Top Link Double Pilot Check Valve 1/4"BSP - 25Lpm - Approved Hydraulics
    Regular price £24.95
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    Top Link Double Pilot Check Valve 1/4"BSP - 25Lpm

    Key Features

    • Application: tractor top link cylinder load holding
    • Type: double pilot operated check
    • Port size: 1/4' bsp
    • Rated flow: 25 to 50 l/min options
    • Use: prevents drift ; allows controlled retraction on pilot
    Regular price £24.95
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  • Top Link Double Pilot Check Valve 3/8"BSP In Lin - 25Lpm - Approved Hydraulics Ltd
    Regular price From £41.32
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    Top Link Double Pilot Check Valve 3/8"BSP In Lin - 25Lpm

    Key Features

    • Application: tractor top link cylinder load holding
    • Type: double pilot operated check
    • Port size: 3/8' bsp
    • Rated flow: 25 to 50 l/min options
    • Use: prevents drift ; allows controlled retraction on pilot
    Regular price From £41.32
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery
  • Hydra Part Top Link Double Pilot Check Valve 1/2"BSP  50Lpm - Approved Hydraulics
    Regular price From £51.83
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    • Delivery to UK & Ireland

    Top Link Double Pilot Check Valve 1/2"BSP 50Lpm

    Key Features

    • Application: tractor top link cylinder load holding
    • Type: double pilot operated check
    • Port size: 1/2' bsp
    • Rated flow: 25 to 50 l/min options
    • Use: prevents drift ; allows controlled retraction on pilot
    Regular price From £51.83
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery
  • Hydra Part Top Link Double Pilot Check Valve 1/2"BSP  50Lpm - Approved Hydraulics
    Regular price £81.46
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    Top Link Double Pilot Check Valve 3/4"BSP

    Key Features

    • Type: double pilot operated check valve
    • Threads: 3/4" BSP
    • Function: locks load until pilot pressure releases checks
    • Use: load holding on cylinders and top links
    • Pressure: 315 to 350 bar class
    Regular price £81.46
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  • HP-LVDT-DIN Double Pilot Check Valves
    Regular price From £32.94
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    HP-LVDT-DIN Double Pilot Check Valves

    Key Features

    • Type: double pilot operated check valve
    • Threads: BSP
    • Function: locks load until pilot pressure releases checks
    • Use: load holding on cylinders and top links
    • Pressure: 315 to 350 bar class
    Regular price From £32.94
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery
  • Double Pilot Operated Check Valve VBPDE 3/8"L  CMP/FLV
    Regular price £66.78
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    Double Pilot Operated Check Valve VBPDE 3/8"L CMP/FLV

    Key Features

    • Ports: G 3/8 BSPP
    • Function: double pilot operated check valve VBPDE
    • Flow rating: 60–80 l.min typical
    • Max pressure: 350 bar
    • Use: load holding on cylinders ; prevents drift
    Regular price £66.78
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  • Double Acting Pilot Check Valves
    Regular price From £44.88
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    Double Acting Pilot Check Valves

    Key Features

    • Function: locks cylinder in position until piloted open
    • Ports: 1/4" ; 3/8" ; 1/2" bspp options
    • Pilot ratio: 3.1 ; 4.1 options
    • Cracking pressure: 3 ; 5 bar typical
    • Use: load holding on da cylinders
    • Mounting: in line block
    Regular price From £44.88
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  • DIN 3/8" BSPP Double Acting Pilot Check Valve With Adjustable Banjo 12mm
    Regular price £34.85
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    DIN 3/8" BSPP Double Acting Pilot Check Valve With Adjustable Banjo 12mm

    Key Features

    • Type: double acting pilot operated check valve with adjustable banjo
    • Ports: 3/8 BSPP
    • Function: locks actuator in both directions until pilot pressure opens
    • Benefit: load holding with controlled release
    • Use: cylinders that must hold position under load
    Regular price £34.85
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery
  • 3/8" BSPP Double Acting Pilot Check Valve
    Regular price £21.17
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    • Delivery to UK & Ireland

    3/8" BSPP Double Acting Pilot Check Valve

    Key Features

    • Type: double acting pilot operated check valve
    • Ports: 3/8 BSPP
    • Function: locks actuator in both directions until pilot pressure opens
    • Benefit: load holding with controlled release
    • Use: cylinders that must hold position under load
    Regular price £21.17
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery
  • BSPP Double Acting Pilot Check Valve - Flanged Version
    Regular price From £46.54
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    • Delivery to UK & Ireland

    BSPP Double Acting Pilot Check Valve - Flanged Version

    Key Features

    • Type: double acting pilot operated check valve
    • Ports: as specified
    • Function: locks actuator in both directions until pilot pressure opens
    • Benefit: load holding with controlled release
    • Use: cylinders that must hold position under load
    Regular price From £46.54
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    • Delivery to UK & Ireland
    • Order by 3pm for Next Day Delivery

Dual Pilot Check Valves

Common Calculations FAQs

Calculating force, speed, pressure, power, and efficiency in hydraulic applications.

How do you calculate actuator speed?

Actuator speed is determined by flow rate and cross-sectional area:

Speed = Flow rate ÷ Area

Flow rate is the volume of fluid delivered (in L/min or GPM).

Area is the cross-sectional area of the actuator piston: π × (diameter ÷ 2)².

How do you calculate cylinder force?

Cylinder force can be calculated using:

Force = Pressure × Area

Pressure is the system pressure (in psi or bar).

Area is the cross-sectional area of the cylinder bore (in square inches or square centimeters).

Area = π × (bore diameter ÷ 2)².

How do you calculate pressure drop across a valve?

Pressure drop can be calculated using the valve flow coefficient (Cv):

Pressure Drop (ΔP) = (Flow Rate)² ÷ (Cv² × Fluid Density)

Flow Rate is the fluid flow (in GPM or L/min).

Cv is the valve flow coefficient.

Fluid Density is the density of the hydraulic fluid.

How do you size an accumulator?

Accumulator sizing considers required flow, pressure, and pre-charge:

Accumulator Volume = Flow Rate × Time ÷ Pressure

This determines how much fluid must be stored to maintain system pressure.

How to convert psi to bar?

Use the conversion factor: 1 bar = 14.5 psi.

To convert psi to bar, divide psi by 14.5.

Example: 200 psi ÷ 14.5 = 13.79 bar.

What is pre-charge pressure in an accumulator?

Pre-charge pressure is the initial gas pressure in the accumulator before fluid enters.

It helps maintain system pressure as the accumulator discharges.

Typically set to 70–80% of system operating pressure.

What is specific gravity of hydraulic fluid?

Specific gravity is the ratio of hydraulic fluid density to water.

A value of 1 means equal density.

Less than 1 means the fluid floats; greater than 1 means it sinks.

What is torque in a hydraulic motor?

Torque is the rotational force produced based on system pressure and motor displacement:

Torque = Pressure × Displacement ÷ 2π

Pressure is the operating system pressure.

Displacement is the volume displaced per revolution (in cubic inches or cubic centimeters).

What unit is hydraulic power measured in?

Hydraulic power is measured in horsepower (HP) or kilowatts (kW).

Hydraulic horsepower can be calculated using:

HP = (Pressure (psi) × Flow rate (GPM)) ÷ 1714.

What’s the relationship between pump speed and flow?

Flow rate is directly proportional to pump speed.

If pump speed doubles, flow rate doubles (assuming constant displacement).

This is important when adjusting flow or selecting a pump for varying speeds.