Air Balancer Selector

A pneumatic balancer (lift assist) holds a load in the air so one person can move it by hand. You enter the load, the stroke, the air supply and the controls you need. The tool sizes the balancer, suggests the type (wire rope, cylinder or rigid arm), checks every model in its database, compares up to five, and writes an RFQ text you can send to suppliers.

What it covers. Wire-rope balancers, cylinder lift assists and rigid-arm balancers from international and Chinese makers (Ingersoll Rand, Knight, Columbus McKinnon, Endo, Scaglia Indeva, PSItaly Dalmec, and Chinese makers). The data comes from catalogues and listings as of Oct 2026.

What it does not do. It is a first selection. The capacity, stroke and air figures must be confirmed with the maker's quote. Chinese entries often come from trader listings that contradict themselves. Structure loads are estimates: they leave out the arm and boom self-weight. The tool does not check the supporting structure, the safety of the lifted load or the local lifting rules.

Who it is for: Merlin design team members who need to pick or specify a balancer for a station.

1. Press the button below. It fills the form with a 160 kg part, 1000 mm stroke, 6 bar supply.
2. Read the suggested type: wire rope, because the load hangs under the hook with no moment.
3. Read the sizing numbers: required rating 200 kg, 230 kg at 6.9 bar (the derating for your 6 bar supply), minimum stroke 1,100 mm, air per lift 20.4 NL, structure load 2.70 kN.
4. In Models, press Wire rope to see only those. Rows marked Fits pass every check. Click a column heading to sort.
5. Tick two or three models and open Compare, then RFQ text and press Copy RFQ text.
6. Change the supply pressure to 5 bar and watch the required rating at 6.9 bar rise from 230 kg to 276 kg and models drop out.

Check by hand. Total load 160 kg ÷ 0.80 utilisation = 200 kg. At 6 bar a balancer rated at 6.9 bar has 6 ÷ 6.9 of its capacity, so the rating needed at 6.9 bar is 200 × 6.9 ÷ 6 = 230 kg. Stroke: 1,000 + 100 margin = 1,100 mm. Structure: (160 + 60) × 1.25 × 9.81 ÷ 1000 = 2.70 kN.

Load the battery pack example Load it with 5 bar supply

01 Application. Five groups of inputs: load, motion, air and duty, controls needed, supporting structure. 02 Sizing. The suggested type and eight numbers that update as you type. 03 Models. Four tabs: Matches (the table), Compare, RFQ text and Add model. 04 How it works gives the formulas and the data confidence. This manual is section 05.

Everything is calculated in your browser. Models you add are kept in this browser only.

• Part weight and tooling. The balancer carries both. Hooks, handles and grippers hung under the rope count as tooling.
• Maximum utilisation. Makers rate the lift capacity at about 80 % of the balance capacity. Keep 80 % unless the maker says otherwise.
• CG offset from hook. How far the centre of gravity is from the hook line. A rope balancer cannot resist a moment, so more than 50 mm points to a rigid arm.
• Vertical stroke and margin. The model's stroke must cover both.
• Horizontal reach. Arm length for a rigid arm or a jib. Leave it at 0 for an overhead rail system.
• Lift speed. Used for the peak air flow.
• Fixed orientation, tool torque, guided placement. These tick-boxes steer the suggested type.
• Pressure at the drop. The lowest pressure at the balancer after line losses and the FRL.
• Cycles per hour. Used for the average air flow.
• Float, dual load, pendant. A model without a listed control is removed (shown as No).
• Balancer and trolley weight, impact factor. For the supporting structure load. 1.25 is a common allowance; use your own design code.

Fit. Fits means the load is within your utilisation limit at your pressure, the stroke and reach are enough and the controls you asked for are listed. Tight holds the load but is above your utilisation limit. Check means something is not published (capacity, stroke, reach) or the entry is a range, so confirm the size. No fails a check; these rows are hidden until you tick Show models that don't fit.

At your bar. Rated capacity × (your bar ÷ rated bar), never above the rating. If the maker does not publish a rated pressure the tool assumes 7 bar and says so.

Utilisation bar. Green when within your limit, amber when above it, red when over capacity.

Air per lift is a calculated estimate in normal litres of free air. The page shows a published figure beside it when the maker gives one. Data confidence shows whether a model comes from a datasheet, a website or is estimated.

Filters. Type, origin, brand, India channel (subsidiary or distributor) and a text search over model, series and features.

Compare. Tick up to five models in Matches. The Compare tab lists them side by side with every attribute and a link to the source.

RFQ text. A ready-to-send request for quotation with your load, motion, air supply, controls and safety, the structure load, what to confirm (capacity against pressure curve, behaviour on air loss, CE and load-test certificates, service in India), and the models under consideration (the ones you ticked, or the first five that fit). Type the station name first, then press Copy RFQ text.

Add model. Add a quoted model or a brand that is not listed: brand, model, type, origin, rated capacity, stroke, reach and rated pressure. It appears in Matches tagged YOURS. Entries are saved in this browser only, so they do not travel to another computer.

Rigid arm for an off-centre part. A 40 kg part and 12 kg of tooling with the CG 150 mm off the hook, held at a fixed orientation, on a 2 m jib. The suggested type is a rigid arm. Required rating 65 kg (75 kg at 6.9 bar). Structure load (52 + 60) × 1.25 × 9.81 ÷ 1000 = 1.37 kN, base moment 1.37 × 2.0 m = 2.75 kN·m.

Load the jib example

Cylinder for short guided placement. A 25 kg part with 5 kg of tooling, 600 mm stroke, guided placement. The suggested type is a cylinder. Required rating 38 kg. Cylinder-type data is thin: most cylinder lift assists are built to order, so expect to ask the maker.

Load the cylinder example

• Forgetting the tooling. The gripper often weighs more than people think.
• Using the compressor pressure. Use the pressure at the balancer after the filter, regulator and hose.
• Picking a rope balancer for an off-centre load. It swings and cannot hold the part's orientation.
• Oversizing. A larger balancer uses more air for the same part.
• Trusting trader listings. Ask for the CE technical file, a load-test certificate and the capacity against pressure curve.
• Using the structure load as a final design. Add the arm and boom weights from the maker's drawing and apply your own safety factors.

• v1 · 12 Oct 2026
  Converted to the site format. Sizing, type advice, a database of balancers from international and Chinese makers, filters, compare, RFQ text, add your own model, formulas and data notes, and this manual with examples.