HBS Hydraulic Cylinder Usage & Maintenance Guide

700 bar

Max. Operating Pressure

3/8″

NPT/F Connection Standard

2

System Type: Single / Double-Acting

Before Commissioning

Pre-Use Checklist

Visually inspect the body and piston surfaceConfirm there's no visible damage, pitting, or oil leakage

Verify the pump's pressure classConfirm the pump you'll use is rated for the 700 bar class

Tighten hoses and connectionsCheck that the 3/8″ NPT/F connections aren't loose

Make sure the base surface is flat and solidThe cylinder must sit on ground with no risk of tipping or sliding

Align the load axis with the cylinder axisOff-axis (eccentric) loading shortens piston and seal life

Clear the working areaMake sure no one or nothing obstructs the load path or stroke distance

Operating Steps

Commissioning and Operation

Positioning

Place the cylinder on its base plate, aligned with the load axis, on a flat surface. If using HBS-DL, align the hollow-plunger bore with the stud/shaft axis.

Connection

Connect the hose securely to the 3/8″ NPT/F port. On double-acting models like HBS-CT, make sure the push and pull lines are connected to the correct directions.

Gradual Pressurization

Bring the pump online gradually; rather than jumping straight to 700 bar, proceed while observing that the load moves smoothly and stays balanced.

Monitor Under Load

Watch that the load advances at a steady speed and stays balanced throughout the stroke; if you notice unusual noise, vibration, or leakage, release pressure immediately.

Release Pressure

Once the operation is complete, release line pressure in a controlled, gradual manner; avoid sudden release.

Return and Shutdown

On single-acting series (GA/DP/DL), the internal return spring retracts the piston. On HBS-CT, controlled pressure is applied to the pull line for return. After disconnecting the hoses, cap the connection ports.

// GENERAL TECHNICAL SUMMARY

PRESSURE Max. 700 bar

CONNECTION 3/8″ NPT/F (CT: 2 lines)

BODY 7075-T6 aluminum, hard-anodized

For model-specific stroke, capacity, and dimension figures, refer to the model table on the relevant product page.

⚠ Safety Warnings

Never exceed the maximum 700 bar operating pressure under any circumstances; verify your pump's pressure class before every use.
Never leave a load supported solely by the cylinder in a suspended/held position; use mechanical blocking or cribbing for any sustained (extended) support.
Never stand or place a hand in the movement path of, or beneath, a loaded cylinder.
Use the cylinder only within its specified capacity and stroke limits; never force beyond capacity.
Inspect hoses and connections for leaks, wear, or damage before every use.
Never apply an off-axis (eccentric) load; the load must always be aligned with the piston axis.
On double-acting models like HBS-CT, don't mix up the push/pull lines; an incorrect connection can cause unexpected motion.

// This guide summarizes general usage and maintenance principles; it does not replace the technical documentation or operator instructions specific to your application. For critical or high-risk applications, we recommend contacting the Hydro Bard engineering team.

Periodic Maintenance

Recommended Maintenance Intervals

Interval	Inspection / Maintenance Task
Before Every Use	Visual leak/damage check, connection tightness, base surface stability
After Every Use	Fully retract the piston, clean the body surface, cap the connection ports
Monthly (heavy use)	Seal condition and piston surface wear check, return spring response (single-acting models)
Every 6 Months	Hydraulic oil cleanliness/level, hose integrity, anodized coating surface check
Annually	Comprehensive teardown inspection, seal kit replacement assessment, calibration/performance test

// These intervals are general industry-practice recommendations; actual maintenance frequency varies with usage intensity, environmental conditions, and application criticality. More frequent inspection is recommended for heavy or continuous use.

Why It Matters

Why Does Proper Maintenance Make a Difference?

The HBS series' 7075-T6 aluminum alloy body and hardened piston surface are engineered to deliver a long service life when used correctly. But as with any hydraulic equipment, performance and safety depend on regular inspection and timely intervention. Checking the seal kit without delay at the first sign of leakage or wear prevents both unexpected failures and loss of power at critical moments. The HBS series' standard seal kits and modular design let you complete this maintenance in the field, quickly and at low cost.

FAQ

Frequently Asked Questions

Which hydraulic oil should be used with an HBS series cylinder?

The right hydraulic oil type is determined primarily by your pump's operating manual. In general, the standard mineral-based hydraulic oils used in 700 bar class systems are compatible with the HBS series; for a specific viscosity or brand recommendation, contact the Hydro Bard engineering team.

The cylinder is losing pressure or retracting slowly — why?

The most common causes of pressure loss are loose hose connections, worn seals, or insufficient pressure on the pump side. On single-acting (spring-return) models, slow retraction is usually caused by contaminated oil or a fatigued return spring. If there's no leak, check the connections and oil level first; if the problem persists, the seal kit may need to be evaluated.

When does the seal kit need to be replaced?

We recommend checking the seal kit whenever you notice visible oil leakage on the piston surface, loss of pressure holding, or unusual friction during movement. The HBS series has a modular design with standard seal kits; confirm the correct kit code with Hydro Bard before replacement.

How should I store the cylinder when it's not in use?

Store the cylinder with the piston fully retracted, in a dry, dust-free environment, with the connection ports capped. For long-term storage, protecting the body surface with a light film of protective oil helps preserve the anodized coating.

What's different about maintenance on double-acting models like HBS-CT?

On the double-acting HBS-CT series, both the push and pull lines need to be checked independently; unlike the single-acting series, return is achieved with hydraulic pressure rather than a spring, so the connection tightness and seal integrity of both lines need to be checked separately.

Need a seal kit or spare part? Send us your model code — Hydro Bard will provide the correct service kit and technical support.

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Safe Operation and Maintenance for a Longer Service Life