MSA-125 Spare Parts FAQs
Straight answers to the questions people ask most when finding and fitting spare parts for a 125 mm articulated fume extraction arm.
How is an extraction arm balanced?
Arms are designed to stay where you put them. Depending on the design, this may be done with gas springs, mechanical springs, counterweights or friction joints. A balance system counters the weight of the arm and hood so it moves with light effort.
If the arm drifts or sags, check the balance parts first, then the joints and fixings. Use the data plate and manual to see how your own arm is balanced, and replace parts only with the correct version for your arm.
How do I choose the right gas spring?
Gas springs are rated by force, and the right rating depends on the arm size and what is fitted to it. Too weak and the arm sags, too strong and it rises or is hard to pull down.
Match the new spring to the old one by the rating marked on it, or to the spare listed for your exact arm. Some springs come with a hole plate or fittings, so check what is included and that it suits your mechanism.
Is it safe to replace gas springs myself?
A competent person can do it by following the maker's instructions. The springs are pressurised and the arm can move suddenly when a spring is released, so support the arm, wear eye protection and gloves, and keep fingers clear of pinch points.
Never drill, cut or heat a gas spring. Take the arm out of use while you work, and test the balance before it returns to service. If in doubt, use a qualified engineer.
What are bushings in the arm joints, and when should they be replaced?
Where fitted, bushings are small bearing sleeves in the joints. They let the arm pivot smoothly and take the wear in place of the arm body. Over time they wear, and joints become loose, noisy or sloppy.
If an arm wobbles or will not hold its position even when the balance parts are good, worn bushings may be the cause. Check the parts list for your arm, replace bushings as a set, and keep the pivots clean.