40MM NATO (RD40X1/7) to Honeywell Sperian® Filter Adapter

thingiverse

This prototype design for a 40 MM NATO (RD40x1/7), gas mask thread, to Honeywell Sperian Filter Adapter. This adapter makes any RD40x1/7 threaded full face CBRN masks compatible with Honeywell Sperian line of legacy chemical, combination, and particle filter cartridges to help mitigate PPE shortages by expanding greater cross compatibility of respirators and filters to other manufacturer models. Part Description: ============== 40MM_TO_SPERIAN_FILTER_ADAPTER_M30X1.8_GEN1.stl Single piece construction adapter for Honeywell Sperian legacy filters that do not require clocking. Due to the M30 diameter of threads encroaching on the nominal wall thickness of the two piece clocking outer shell adapters ID of 31 and 31.75 mm respectively, decided not to make a backwards compatible two piece construction version. Disclaimers/Risks: =============== 1.) Use Proper Gaskets It would appear that the Honeywell Sperian respirators have gasket installed on filter side, however please ensure gasket or o-ring is properly installed between assembly joint for proper seal. 2.) Perform Proper Negative Pressure Test Follow SSPs established by your institution or workplace for further guidance. But in general, don your respirator, adjust straps till taught against face, ensuring no obstructions around the periphery of the seal against face either due from hair, facial hair, or otherwise. Exhale deeply. Cover all inhalation ports. (Typically, most full face or half face respirators have two filters, so cover those intake ports with your hands. If running only one filter, ensure opposite port has filter cap in place.) Now inhale deeply. The mask should suck tightly against your face without any air leakages. Re-test if adjustments are required at gasket/o-ring interfaces at the adapter. 3.) Use At Own Risk – Temporarily Solution Only Until Supply Chain Normalizes 3D printing materials are not resistant to many solvents, are water soluble, and degrade when exposed to chemicals, heat, and UV/sunlight. 3D printing this adapter is only a temporarily ad-hoc solution against biological contagions. In addition to using a properly calibrated 3D printer, due to tolerances of adapters, if possible perform hot nozzle pass on all exterior surfaces, to reduce surface porosity. Highly recommended users apply a thin layer of polyurethane clear coat on all exterior surfaces, spray or dip based methods, to help resiliency and durability for repeated sterilization and to reduce fomite transmission in printed infill layers. Once supply chains return to normal, users should purchase OEM OSHA/NIOSH/EN standard approved respirators, adapters and accessories for their institution and workplaces. Dev. Notes: ======== 04/18/2020 - Initial model release. I do not have any Sperian series respirators or filters to check measurements, so please report back in comments for any fitment issues and I'll release revisions as required. Credits: ====== Thanks to midnightsmith publishing the 3M adapter version of this legacy respirator thread that allows the 3D printing community to reference legacy filters that the general population may have older stock or inventory of allowing the maximum cross compatibility of COTS filter cartridges.