Lincoln Helmet Spares FAQs
Spares for one maker's helmets and powered air units: what wears, how to match parts and how to check them.
What should I do if the fan stops or the airflow drops?

Stop welding at once and leave the work area. Do not keep working if the fan stops or the airflow drops, because the helmet then no longer gives the protection it was designed for. Keep the helmet on until you are clear of the fume, as dangerous contaminants may not be visible or smellable.
Once you are in clean air, check the battery, filters, hose and connections. A flat battery or blocked filter is a common cause. If you cannot find and fix the fault, replace the faulty part with one the maker specifies, or have the unit examined by a competent person before using it again.
Who can repair a powered helmet, and how often should it be checked?

Follow the maker's maintenance instructions, including any replacement periods for filters and other parts. Simple jobs such as cleaning and fitting a new filter can be done by the wearer if the manual allows it. Repairs and fault finding should be done by a competent person, using parts from the original maker where possible.
HSE guidance on respiratory protective equipment says reusable equipment should have thorough maintenance, examination and testing at least once a month, or before use and at least every three months if it is only used occasionally. Keep records of examinations, tests and repairs for at least five years, and check the unit yourself before every use.
What does the optical class on a helmet filter mean?

Auto-darkening welding filters carry an optical class written as four numbers, such as 1/1/1/1. Each number grades one property from 1 (best) to 3: the quality of the view (distortion), light scatter, how even the darkness is across the lens, and how the darkness changes when viewed at an angle. The standard behind this marking has been updated, so newer filters may quote a newer standard.
The first three matter most in everyday welding because they affect what you see all the time. The fourth matters mainly when looking at the arc from a sharp angle. When replacing a filter, check that its class is not lower than the original and that it is intended for your helmet.
Why do parts that look alike not fit every helmet?

Helmets from the same maker are often built in several series, and the lens openings, frames, clips and fixings differ. A part may look the same but be a few millimetres different in size, or have a different fixing.
Look up the helmet name or series on the helmet itself or in the manual, then match the part number or description. Many parts are listed against specific helmet models, which is why this category is organised by helmet type. If the markings have worn off, compare the old part carefully or ask the supplier. Do not force a part that does not seat easily.