JRT inverted long-stroke hydro-pneumatic booster cylinder — JiuRong
Inverted Long-Stroke Series

JRT Inverted Long-Stroke Hydro-Pneumatic Booster Cylinder

Upward pressing. Purpose-built inverted mounting.

The JRT is JiuRong's inverted-mount hydro-pneumatic booster cylinder — the rod extends upward, delivering 1–40 tons of high-pressure force from below the workpiece. Built on the same compact side-by-side architecture as the JRP, but with a purpose-designed inverted oil circuit and back-side port distribution. Not a flipped standard cylinder — an engineered upward-pressing solution.

1–40TUpward output force
Ø63–160Bore range (mm)
50–400Total stroke (mm)
25–45Cycles / min
Configure Your JRT View Dimensions
Why JRT

Why Choose the JRT Inverted Series?

When your workpiece sits above the cylinder and force must push upward — bottom-up pressing, lifting-clamping, or die-lift applications — a standard downward-pressing cylinder cannot simply be flipped upside down. The oil reservoir, air passages, and return circuit depend on gravity. The JRT is purpose-engineered for inverted mounting: same compact side-by-side package as the JRP, but with an inverted oil circuit, back-side port layout, and upward rod extension.

JRP — Rod Down (Standard)

Force down Workpiece above

Cylinder above workpiece, rod extends downward. Gravity feeds oil to the booster.

JRT — Rod Up (Inverted)

Force up Workpiece above

Cylinder below workpiece, rod extends upward. Inverted oil circuit ensures reliable booster feed regardless of orientation.

Why Not Just Flip a Standard Cylinder?

A standard in-line or side-by-side cylinder relies on gravity to keep hydraulic oil at the booster intake. Flipping it upside down starves the booster, causes air entrainment, and leads to inconsistent force output — or complete failure. The JRT's internal oil passages, reservoir geometry, and return circuit are designed from the start for inverted operation, ensuring every cycle delivers rated tonnage upward.

Purpose-Built Upward Force

Rod extends upward to press, clamp, or lift from below — 1 to 40 tons of high-pressure output from standard 4–7 kgf/cm² shop air. No hydraulic power unit needed.

Compact Side-by-Side Package

Pneumatic and hydraulic cylinders run in parallel, keeping the axial envelope short — ideal for mounting under a worktable or platen where vertical headroom is limited.

Long Approach Stroke

Total strokes from 50 to 400 mm — the pneumatic approach stage extends upward quickly at low force, then the hydraulic power stroke engages for the final 5–20 mm at full tonnage.

Back-Side Port Distribution

Air ports are routed to the back face of the cylinder body, keeping the top (working) surface clean and unobstructed — easier plumbing when mounted under a fixture or table.

Fast Cycle Rate

25–45 cycles per minute with approach speeds up to 400 mm/s. The two-stage principle keeps air consumption low while maintaining throughput in automated lines.

JRT + JRP Matched Pair

For machines that press from both sides — top and bottom — the JRT (up) and JRP (down) share the same bore, stroke, and mounting footprint, simplifying frame design and spare parts.

Operating Principle

How the JRT Works

The JRT uses the same proven two-stage hydro-pneumatic principle as the JRP — a fast low-force pneumatic approach followed by a short high-force hydraulic power stroke — but the rod travels upward and the internal oil circuit is designed for inverted operation. Below: the force-displacement profile, the four-step upward cycle, and the pneumatic circuit.

Force vs. Displacement Profile

0 Approach force Power force 0 Upward approach stroke (50–400 mm) Total Power stroke (5–20 mm) Pneumatic approach — fast, low force Hydraulic boost Workpiece contact Displacement ↑ Force ↑

The rod extends upward on compressed air for the long approach stage. On workpiece contact, the hydraulic booster engages for the final 5–20 mm at full tonnage — pushing upward.

Four-Step Upward Cycle

  1. 01
    Pneumatic Approach (Up)

    Solenoid valve DT1 energizes. Shop air drives the piston upward at high speed (up to 400 mm/s) with low force — covering the full approach stroke with minimal air consumption.

  2. 02
    Workpiece Contact

    The upward-moving ram contacts the workpiece from below. Pneumatic force alone is insufficient for the operation — this triggers the hydraulic boost phase.

  3. 03
    Hydraulic Power Stroke (Up)

    Solenoid valve DT2 energizes. The booster piston pressurizes the hydraulic oil through the inverted oil circuit, multiplying force to rated tonnage (1–40T) for the final 5–20 mm of upward travel.

  4. 04
    Pressure Release & Return (Down)

    DT2 de-energizes to release hydraulic pressure, then DT1 de-energizes. The double-acting pneumatic return retracts the rod downward to home position — ready for the next cycle.

Pneumatic Circuit Diagram

JRT inverted hydro-pneumatic cylinder pneumatic circuit diagram showing DT1 and DT2 solenoid valves and back-side port layout
DT1 — Approach / return solenoid valve
DT2 — Booster solenoid valve
Booster cylinder (inverted side-by-side)
Air-over-oil tank (inverted feed)
Air filter / regulator / lubricator (FRL)
Muffler / exhaust port
Specifications

Technical Specifications

Standard JRT series parameters. All models operate on standard shop air (4–7 kgf/cm²) and use VG68 anti-wear hydraulic fluid. The inverted oil circuit is designed for upward rod extension. Custom bore, stroke, and force configurations available on request.

Performance

High-pressure output force
1–40 tons (nominal)
Operating air pressure
4–7 kgf/cm² (0.4–0.7 MPa / 4–7 bar)
Bore diameter
Ø63 / 80 / 100 / 125 / 150 / 160 mm
Total stroke (approach)
50 / 100 / 150 / 200 / 300 / 400 mm
Power stroke (high-pressure)
5 / 10 / 15 / 20 mm
Cycle rate
25–45 cycles / min
Operating speed
50–400 mm/s
Operating temperature
0–60 °C

Construction

Actuation
Double-acting
Cylinder arrangement
Side-by-side (pneumatic + hydraulic in parallel)
Mounting orientation
Inverted, rod-up (upward pressing)
Oil circuit
Inverted gravity-independent design
Hydraulic fluid
VG68 anti-wear hydraulic oil
Hydraulic proof pressure
120 kgf/cm² (12 MPa)
Pneumatic proof pressure
30 kgf/cm² (3 MPa)
Rod treatment
Hardened & ground alloy steel, chrome plated

Interface & Control

Air supply port
ZG3/8" – ZG1 1/2" (by model)
Port distribution
Back-side (rear face) routing
Control valves
Two 5/2-way solenoid valves (DT1, DT2)
Control voltage
DC 24 V (standard) / AC 220 V (optional)
Rod end thread
M30×1.5 – M100×3 (by model)
Position sensing
Magnetic reed / solid-state switches (optional)
Noise level
≤ 75 dB(A) at 1 m
Seals
NBR / polyurethane, service-replaceable
Dimensions

Installation Dimensions

Standard JRT installation dimensions by bore size. Total length (N) varies with power stroke selection (5/10/15/20 mm). Port G indicates the back-side air port distribution dimension. All dimensions in mm unless noted. Custom configurations available on request.

Ø63 mm
Ø80 mm
Ø100 mm
Ø125 mm
Ø150 mm
Ø160 mm

Ø63 mm Bore — All Tonnage Options

TonABCDE F (Port)G (Back port) HIJK (Rod thread) LM N (5mm)N (10mm)N (15mm)N (20mm) OPQR
5T 180 150 132 227.5 14 ZG3/8" 345 35 35 22 M30x1.5 117 130 369 454 539 624 75 95 100 130
10T 160 132 122 227.5 14 ZG3/8" 345 35 35 22 M30x1.5 115 130 395 471 547 623 75 95 100 130

N = total installed length at the selected power stroke (5/10/15/20 mm). G = back-side air port distribution center distance. All other dimensions are constant regardless of power stroke. Scroll horizontally to view all columns on small screens.

Ø80 mm Bore — All Tonnage Options

TonABCDE F (Port)G (Back port) HIJK (Rod thread) LM N (5mm)N (10mm)N (15mm)N (20mm) OPQR
5T 190 160 155 275 17 ZG3/8" 405 45 45 28 M30x1.5 135 150 410 500 590 680 95 120 130 160
10T 190 158 145 275 17 ZG3/8" 405 45 45 28 M30x1.5 130 150 440 535 630 725 95 120 130 160
15T 225 195 180 345 22 ZG1/2" 495 50 50 35 M40x2 165 190 520 627 734 841 120 150 160 200

N = total installed length at the selected power stroke (5/10/15/20 mm). G = back-side air port distribution center distance. All other dimensions are constant regardless of power stroke. Scroll horizontally to view all columns on small screens.

Ø100 mm Bore — All Tonnage Options

TonABCDE F (Port)G (Back port) HIJK (Rod thread) LM N (5mm)N (10mm)N (15mm)N (20mm) OPQR
10T 235 215 190 345 22 ZG1/2" 495 50 50 35 M40x2 190 190 638 760 882 1004 140 180 190 235
15T 200 190 170 310 22 ZG1/2" 455 50 50 35 M40x2 165 175 625 750 875 1000 120 150 160 200
20T 290 270 245 430 29 ZG3/4" 620 60 60 45 M56x2 235 260 750 895 1040 1185 175 220 235 295

N = total installed length at the selected power stroke (5/10/15/20 mm). G = back-side air port distribution center distance. All other dimensions are constant regardless of power stroke. Scroll horizontally to view all columns on small screens.

Ø125 mm Bore — All Tonnage Options

TonABCDE F (Port)G (Back port) HIJK (Rod thread) LM N (5mm)N (10mm)N (15mm)N (20mm) OPQR
10T 300 290 260 460 31 ZG3/4" 660 60 60 45 M56x2 310 340 950 1135 1320 1505 240 300 320 400
15T 290 270 245 430 29 ZG3/4" 620 60 60 45 M56x2 235 260 750 895 1040 1185 175 220 235 295
20T 300 290 260 460 31 ZG3/4" 660 60 60 45 M56x2 310 340 950 1145 1340 1535 240 300 320 400

N = total installed length at the selected power stroke (5/10/15/20 mm). G = back-side air port distribution center distance. All other dimensions are constant regardless of power stroke. Scroll horizontally to view all columns on small screens.

Ø150 mm Bore — All Tonnage Options

TonABCDE F (Port)G (Back port) HIJK (Rod thread) LM N (5mm)N (10mm)N (15mm)N (20mm) OPQR
20T 360 350 320 565 38 ZG1" 805 80 80 60 M64x2 420 460 1260 1500 1740 1980 340 420 450 560
30T 300 290 260 460 31 ZG3/4" 660 60 60 45 M56x2 310 340 950 1145 1340 1535 240 300 320 400
40T 360 350 320 565 38 ZG1" 805 80 80 60 M64x2 420 460 1290 1540 1790 2040 340 440 470 590

N = total installed length at the selected power stroke (5/10/15/20 mm). G = back-side air port distribution center distance. All other dimensions are constant regardless of power stroke. Scroll horizontally to view all columns on small screens.

Ø160 mm Bore — All Tonnage Options

TonABCDE F (Port)G (Back port) HIJK (Rod thread) LM N (5mm)N (10mm)N (15mm)N (20mm) OPQR
30T 390 380 350 620 43 ZG1 1/4" 883 100 100 70 M80x3 468 510 1484 1764 2044 2324 400 510 540 680
40T 420 410 380 680 46 ZG1 1/2" 963 110 110 80 M100x3 536 585 1670 1990 2310 2630 460 580 620 780

N = total installed length at the selected power stroke (5/10/15/20 mm). G = back-side air port distribution center distance. All other dimensions are constant regardless of power stroke. Scroll horizontally to view all columns on small screens.

Force Data

Theoretical Output Force vs. Air Pressure

Theoretical high-pressure output force in kgf at various supply pressures. Actual force varies with seal friction, back-pressure, and mechanical efficiency. For critical applications, apply a 0.85 derating factor or contact our engineering team.

Bore Nominal Force 4 kgf/cm² 5 kgf/cm² 6 kgf/cm² 7 kgf/cm²
Ø63 mm 5T 1,800 2,250 2,700 3,150
Ø63 mm 10T 3,600 4,500 5,400 6,300
Ø63 mm 15T 5,400 6,750 8,100 9,450
Ø80 mm 5T 2,800 3,500 4,200 4,900
Ø80 mm 10T 5,600 7,000 8,400 9,800
Ø80 mm 15T 8,400 10,500 12,600 14,700
Ø100 mm 10T 4,500 5,625 6,750 7,875
Ø100 mm 15T 6,750 8,438 10,125 11,813
Ø100 mm 20T 9,000 11,250 13,500 15,750
Ø125 mm 10T 9,375 11,719 14,063 16,406
Ø125 mm 15T 14,063 17,578 21,094 24,609
Ø125 mm 20T 18,750 23,438 28,125 32,813
Ø150 mm 20T 12,000 15,000 18,000 21,000
Ø150 mm 30T 18,000 22,500 27,000 31,500
Ø150 mm 40T 24,000 30,000 36,000 42,000
Ø160 mm 30T 30,720 38,400 46,080 53,760
Ø160 mm 40T 40,960 51,200 61,440 71,680

Values are theoretical at 100% efficiency. 1 kgf = 9.807 N. Nominal force ratings are at 6 kgf/cm² supply pressure.

Compare

JRT vs. JRP vs. JRA

The JRT, JRP, and JRA all deliver hydro-pneumatic force from standard shop air. The choice depends on pressing direction and machine envelope. The JRT is the only one purpose-engineered for upward (inverted) pressing.

JRT inverted long-stroke hydro-pneumatic booster cylinder

JRT — Inverted Long-Stroke

Rod up — upward pressing

  • Best for: Bottom-up pressing, die lift, upward clamping
  • Purpose-built inverted oil circuit — not a flipped cylinder
  • Side-by-side compact package, back-side ports
  • 1–40T output, double-acting
  • Mounts under worktable / platen
JRP compact long-stroke hydro-pneumatic booster cylinder

JRP — Compact Long-Stroke

Rod down — downward pressing

  • Best for: Top-down pressing in short axial envelopes
  • Same side-by-side architecture, downward direction
  • Matches JRT bore / stroke / footprint for dual-action machines
  • 1–40T output, double-acting
  • Vertical mount, rod-down
JRA standard pre-press hydro-pneumatic cylinder

JRA — Standard Pre-Press

In-line, rod down

  • Best for: Conventional top-down pressing with ample space
  • In-line cylinder arrangement — longer axial envelope
  • Widest bore and tonnage range (up to 100T)
  • Most cost-effective when envelope allows
  • Vertical or horizontal mount
Selection Guide

How to Select a JRT

Follow these seven steps to configure the right JRT for your upward-pressing application. Our engineering team can review your requirements and confirm the selection.

  1. 1
    Confirm Upward Pressing Direction

    The JRT is for applications where the cylinder sits below the workpiece and the rod pushes upward. If your force direction is downward, choose the JRP (compact) or JRA (standard) instead. If you need both directions on the same station, use a matched JRT + JRP pair.

  2. 2
    Determine Required Force

    Calculate the pressing, forming, clamping, or lifting force your process requires. Select a nominal tonnage that provides at least 15% margin over the calculated requirement. Refer to the force table above for actual output at your shop air pressure.

  3. 3
    Choose Bore Size

    Bore determines the available tonnage options: Ø63 for 5–15T, Ø80 for 5–15T, Ø100 for 10–20T, Ø125 for 10–20T, Ø150 for 20–40T, Ø160 for 30–40T.

  4. 4
    Set Approach Stroke

    The total (approach) stroke is the upward travel from home position to workpiece contact. Standard options: 50, 100, 150, 200, 300, 400 mm. Choose the shortest stroke that clears your tooling — longer strokes increase the N dimension.

  5. 5
    Set Power Stroke

    The high-pressure power stroke is the final 5–20 mm of upward travel where full tonnage is applied. Standard options: 5, 10, 15, 20 mm. This should be just enough to complete the operation — not the full travel distance.

  6. 6
    Verify Mounting & Port Clearance

    Check the installation dimensions table for your selected bore. Confirm the back-side port location (dimension G) and mounting bolt pattern (O, P, Q, R) fit your machine frame. Ensure plumbing access from the rear when mounted under a table.

  7. 7
    Check Return Force & Duty Cycle

    Confirm the double-acting pneumatic return can overcome any die spring or stripping force on the downstroke. The JRT is rated for 25–45 cycles/min; contact engineering for sustained high-cycle applications above 40/min.

Configure

Build Your JRT Model Number

Select your bore, tonnage, and strokes below. The model number updates automatically — use it when requesting a quote.

4567
Your Model Number JR-T-100-100-10L-15T
Estimated Output Force 0 kgf
Applications

Where the JRT Fits

The JRT is specified whenever force must be applied upward from below the workpiece — bottom-up pressing, die lifting and clamping, or machines where the actuator mounts under the work surface. Common applications include:

Bottom-Up Pressing

Pressing, forming, and embossing from below the workpiece — the cylinder mounts under the die or platen and pushes upward, keeping the top of the machine clear for loading and tool changes.

Die Lift & Clamping

Lifting die halves, clamping workpieces from below, and ejecting finished parts upward out of fixtures — the long approach stroke raises the part, then the power stroke locks it with tons of force.

Riveting & Clinching (Upward)

Self-pierce riveting and clinching operations where the anvil is on top and the setting force comes from below — common in automated assembly lines with overhead tooling.

Precision Insertion (Upward)

Bearing insertion, bushing press-fit, and pin installation from below — the controlled approach speed prevents part damage before the high-force upward press-fit stroke.

Dual-Action Press Stations

Machines that press from both top and bottom simultaneously — pair a JRT (up) with a JRP (down) for matched force, shared footprint, and simplified spare parts.

Custom Automation & Rotary Tables

Automated assembly lines, rotary index tables, and custom machinery where the actuator must fit beneath the work surface — back-side ports keep the top face clean for fixturing.

Engineering Review

Engineering Boundaries

The JRT is a robust and proven inverted design, but the following conditions require engineering review before final selection. Contact our team with your application details — we will confirm suitability or recommend a modified configuration.

Lateral Loads / Side Force

The upward-extending rod is designed for axial force only. Guide the tooling separately if the process applies lateral or offset loads to the ram.

Non-Inverted Mounting

The JRT is purpose-built for inverted (rod-up) operation. Do not mount it rod-down or horizontally — use the JRP or JRA for those orientations.

Long Stroke + High Cycle Rate

Approach strokes above 200 mm combined with cycle rates above 35/min may require a high-cycle seal package and increased lubrication.

Return Stroke Load

If the downward return must overcome significant die spring, stripping, or part-weight force, verify the double-acting return capacity at your supply pressure.

High-Temperature Environments

Ambient temperatures above 60°C require fluoroelastomer (FKM) seals and high-temperature hydraulic fluid.

Custom Stroke or Force

Strokes beyond 400 mm, force above 40T, or non-standard bore combinations are available as engineered specials — contact us with your requirements.

FAQ

Frequently Asked Questions

What is an inverted press cylinder?

An inverted press cylinder is a hydro-pneumatic booster cylinder designed to be mounted upside down relative to a standard cylinder — the rod extends upward instead of downward. It is used when the workpiece sits above the cylinder and force must be applied from below (bottom-up pressing, die lift, upward clamping). The JRT is JiuRong's purpose-built inverted series, with an internal oil circuit engineered for upward operation rather than a standard cylinder simply flipped over.

How does the JRT differ from the JRP?

The JRT and JRP share the same compact side-by-side architecture, bore range (Ø63–160 mm), force range (1–40T), and stroke range (50–400 mm). The difference is pressing direction: the JRP rod extends downward (standard top-down pressing), while the JRT rod extends upward (inverted bottom-up pressing). The JRT also features a purpose-designed inverted oil circuit and back-side port distribution. For dual-action machines that press from both sides, the JRT and JRP can be used as a matched pair with identical mounting footprints.

Can I use the JRT for upward pressing?

Yes — that is exactly what the JRT is designed for. The JRT is purpose-built for upward pressing applications where the cylinder mounts below the workpiece and the rod pushes upward. Its inverted oil circuit ensures reliable booster feed and consistent force output regardless of the upside-down orientation. It is suitable for bottom-up pressing, die lifting, upward clamping, riveting from below, and dual-action press stations.

What direction does the JRT press — up or down?

The JRT presses upward. The rod extends from the top of the cylinder body to apply force from below the workpiece. On the return stroke, the double-acting pneumatic circuit retracts the rod downward to home position. If your application requires downward pressing, choose the JRP (compact side-by-side) or JRA (standard in-line) instead.

Can I just flip a standard cylinder upside down instead of buying a JRT?

No. A standard hydro-pneumatic cylinder relies on gravity to keep hydraulic oil at the booster intake. Flipping it upside down starves the booster chamber, causes air entrainment in the oil, and leads to inconsistent force output, spongy ram action, or complete failure to reach rated tonnage. The JRT's internal oil passages, reservoir geometry, and return circuit are designed from the start for inverted operation, ensuring every upward cycle delivers rated tonnage reliably.

How does the oil circuit work in an inverted cylinder?

In the JRT, the oil reservoir and booster passages are arranged so that hydraulic oil is positively fed to the booster piston regardless of orientation. During the approach stroke, air pressure on the oil surface drives oil into the working chamber; when the booster valve (DT2) energizes, the booster piston displaces oil at high pressure into the upper chamber to generate tonnage. On return, the double-acting pneumatic circuit pushes oil back to the reservoir. The geometry ensures no air pocket can form at the booster intake when mounted upside down.

What bore sizes are available for upward pressing?

The JRT is available in six bore sizes: Ø63, Ø80, Ø100, Ø125, Ø150, and Ø160 mm. Force ranges from 1 to 40 tons depending on bore and tonnage selection. The Ø63 and Ø80 bores cover 5–15T, Ø100 and Ø125 cover 10–20T, and Ø150 and Ø160 cover 20–40T. All bores support total strokes from 50 to 400 mm and power strokes of 5–20 mm. Use the configurator above to build your model number.

Resources

Documentation & Support

2D / 3D CAD Models

Step, IGES, and DWG files for all bore and tonnage combinations.
Online Configurator

Build your model number and get an estimated output force in real time.
Engineering Support

Talk to our application engineers for selection review and custom solutions.

Need an Upward-Pressing Solution?

Send us your JRT model number and application details — our engineering team will confirm the selection and provide a quote within 24 hours.

Get a Quote Configure Your JRT