Weighing Module FAQ: check the installation in this order

F1 How do I size a weighing module?

Use the industry rule dead load + live load ≤ rated capacity × number of modules × 70% to check the capacity per module, then move up to the next capacity step (source: public technical literature).

Worked example: dead load (vessel) 2 t + live load (product) 3 t = 5 t → 3 modules, at 70% → rated capacity per module ≥ 5 ÷ (3 × 0.7) ≈ 2.38 t → take the 3 t module.

Actions

1. Get two figures: the vessel weight and the maximum product weight (ask the process or maintenance department).
2. Count the support legs: the number of support points sets the number of modules.
3. Work out the capacity per module, then take the next step up (within 0.22–2.2 t / 4.4 t / 9 t / 13.6 t / 20 t or 0.5–3 t / 5 t / 10 t / 15–20 t).

Criterion: the module count follows the actual number of support points; after calculating, take the next capacity step up, never down.

Next step: the full version (how to select, install and verify for four duties) is on Selection & Resources.

F2 Do I need three modules or four?

Three modules suit three-point support, four suit four-point support. On a vessel that already has support legs, the leg count decides.

Actions

1. Count the existing support legs (3 legs → 3 modules, 4 legs → 4 modules).
2. A set normally contains 1 fixed module + 1 semi-floating module, with floating modules for the rest (to absorb thermal movement and installation tolerance).
3. On a new vertical cylindrical vessel, three-point support is more stable; where wind load, sway or vibration is present, or the vessel lies horizontally, four-point support is advisable.

Criterion: module count = number of support points. Do not drop a support point to save one module — that turns the vessel into a cantilever.

Next step: models and capacity steps are on the home page; the structure and module count rules come from public technical material.

F3 The reading is wrong, or nothing reads at all. What do I check first?

Check that the nuts on top of the support screws have been released and the sleeve is free.

Fault-finding order

1. The nuts on top of the support screws were not released / the sleeve is not free ⇒ release the nuts so the sleeve is free again.
2. The capacity is set wrongly: note the distinction — this is the rated capacity of the module, not the span set in the indicator; the vessel's own weight (dead load) must be included (check it with the industry rule dead load + live load ≤ rated capacity × number of modules × 70%, source: public technical literature).
3. The feed pipework is rigid ⇒ change it to a flexible connection, or lengthen the pipe run (a rigid pipe carries part of the real load away from the load cells).
4. A damp junction box, unused entries left open ⇒ plug the unused entries with sealing plugs and fit a protective box outdoors.
5. An unstable supply at the indicator ⇒ a voltage outside the permitted range makes the reading drift; use a stabilised supply.
6. The limit stop has seized (clearance too small, bottomed out by thermal expansion) ⇒ reset the limit-stop clearance so slight movement is possible.

Criteria

• Corner difference (four-corner spread): the acceptance figure is confirmed case by case — please contact us.
• Acceptance: load test weights at 20 % / 50 % / 100 % and measure on three consecutive days, then check whether the drift settles inside the accuracy band.
• Reading the curve: step change → replace the module; smooth climb → compensate or recalibrate first.

Next step: the full table of eight faults is on Selection & Resources. If the reading is still wrong, send us the symptom and a photo of the indicator.

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If WhatsApp does not open, call +86 183 51238137.

F4 The vessel is already installed. Can weighing still be added?

Yes. Fit weighing modules to a tank, hopper or reactor and it becomes a weighing system; the vessel does not have to be rebuilt as a scale platform and no extra floor space is needed.

Three checks on site

1. Measure: vessel weight + maximum product weight → work out the capacity per module with the formula.
2. Check the supports: the module count follows the existing support legs; confirm there is room to fit them at the legs.
3. Check three things: is there a place to weld a test-weight platform on the vessel; is the feed pipework rigid (if so, change it to a flexible connection or lengthen it); will the junction box be rained on or washed down.

Criteria

• The modules fit the legs and a test-weight position can be kept ⇒ the retrofit is workable.
• The pipework is rigid and cannot be changed ⇒ deal with the pipework first, or no amount of calibration will hold.
• Downtime needed, and whether an engineer attends: please contact us. Scope of documentation: please contact us.

Next step: send these five items in one go — vessel weight, maximum product weight, number and layout of the support legs, the material and its characteristics, and the site environment (see Selection & Resources).

F5 Do I have to use test weights? What if the vessel has no test-weight platform?

Yes, use test weights. Test weights are the direct way to tell whether the system is accurate and whether it drifts; a vessel with no test platform is a common regret.

Actions

1. Load test weights at 20 % / 50 % / 100 % and measure on three consecutive days, recording each day.
2. New vessel: weld a test-weight platform at the design stage (normally below the vessel, so weights can be added and removed easily).
3. Existing vessel: assess whether a platform can be added; if it is welded on, isolate the power and follow the earthing rules for welding, so that no current passes through the load cells.
4. With no way to add weights, calibration has to rely on online comparison or a substitute load, and both accuracy and confidence are lower.

Criterion: a test-weight position on the vessel means you can check the system yourself later; without one, every dispute needs outside help, so it is worth adding first.

Next step: on-site service method and response times: please contact us.

F6 How often should the system be calibrated?

Set the interval from the slope of the zero offset, not from a fixed calendar; log the zero more often after a new installation or an indicator change.

Actions

1. After a new installation or an indicator change: log the zero more often (weekly, for example) and watch the trend.
2. Once it is stable: set the calibration interval from the drift rate you observe (shorter if it drifts quickly, longer if it barely moves).
3. After each calibration, record it the same way as the acceptance test (three points, consecutive measurements).

Criterion: a smooth climb with a very small slope ⇒ the interval can be extended; a step change ⇒ check for damage first, rather than calibrating more often.

Next step: recommended intervals and calibration service: please contact us; the drift criteria are on Selection & Resources.

F7 Can you build to my drawing?

Yes, Hengyuan takes on custom-built work; flanges, mounting hole spacing, capacity and cable length are confirmed against your drawing and your duty.

What we need for a custom build

1. The support structure and leg dimensions of the vessel or equipment (or drawings, photographs and the space available).
2. Capacity and module count (the capacity per module from the F1 formula).
3. The site environment: dust, moisture, corrosion, vibration, and whether the area is hazardous.
4. The output required: indicator display, 4–20 mA, or communications to a PLC or DCS.
5. Quantity and application (new installation or retrofit).

Criterion: whether it can be built is confirmed against your drawing and your duty; the supply arrangement (including module frames on their own) is confirmed case by case — please contact us.

Next step: for a hazardous area, Explosion-proof versions are available (Ex ia IIC T6); the exact configuration is confirmed against your working conditions. Send the five items above in one message and we can assess it.

F8 Can you produce under our own brand?

Yes. Hengyuan also runs a 1,000 m² stock warehouse and volume production.

Actions

1. Agree how the branding works (nameplate, packaging, and whether the documentation carries your brand).
2. Agree the model and specification (Hengyuan's existing models, or your own numbering).
3. Agree the batch size and the repeat schedule (first batch, then replenishment).
4. Agree the consistency requirement (the calibration must not change between batches, so the model and the acceptance method are fixed).

Criterion: stable long-term supply rests on a fixed specification and a fixed acceptance method; the factory test procedure: please contact us.

Next step: send the branding scope, the model, the batch size and the schedule; the scale facts are on the home page.

F9 Do you hold stock, and how long is lead time?

Lead time depends on whether the item is a standard product: standard items, some ex stock, others about 1 week; custom and non-standard items are confirmed against the order specification.

Actions

1. Say first whether the item is custom (custom and catalogue items run on different schedules).
2. Give the model or capacity + module count + quantity.
3. Give the date you need it by, and we will answer with a feasible date for that configuration.

Criterion: no lead time is a commitment until the model, the module count and the quantity are known. Hengyuan holds a 1,000 m² stock warehouse (Hengyuan's own figures), but this page makes no "ships ex stock" claim.

Next step: send all seven items at once (vessel weight and maximum product weight / number and layout of the support legs / the material and its characteristics / the site environment / the output required / new installation or retrofit / quantity and required date) ⇒ Selection & Resources.

F10 What does the warranty cover, and is a drifting reading a fault or a calibration issue?

Warranty: 12 months.

An impact fault shows as a step change; long-term drift shows as a smooth climb. Read the curve first, then decide whether to replace or to compensate.

Actions

1. Pull the daily zero record (even a handwritten one) and read the shape of the curve.
2. A step change ⇒ usually damage from impact, overload or moisture ⇒ replace the module with the same specification.
3. A smooth climb ⇒ long-term drift (stress relaxation in the spring element plus ageing of the strain gauge adhesive) ⇒ compensate online or recalibrate first; do not replace the whole set in a hurry.
4. While you are there, clear two frequent causes: has "zero on power-up" been set to disabled, and does automatic zero tracking have a threshold and is it disabled during loading.

Criteria

• The shape of the curve decides: step change → replace; smooth climb → compensate or recalibrate first.
• Cost order of the remedies (as published in the source, not re-ranked here): automatic zero tracking < online automatic calibration ≈ dual load cell redundancy > drift model correction > fitting higher-stability load cells.

Next step: to have a curve judged, send the daily zero record (a photograph or a table); the acceptance method is on Selection & Resources.