I have recently changed a set of Butbro (UK brand) multistage OA regs as I have never been that pleased with them, pressure fluctuations, low level chattering causing flame variation. I purchased Murex multistage and they seem much better. My question relates to the presence of inlet filters in the stem attaching to the bottle. Years ago I read that these were beneficial and possibly for reasons other than just filtration. I noted that both Butbro regs had no filters, whereas both Murex have sintered filters fitted. Examination of some other regs showed cheap no name regs not having filters and seemingly better regs having them including a propane reg I have. IIRC some old BOC regs I had had filters fitted and these were considered a quality brand. I also noted that the Butbro regs have a machined recess in the stem that looks like it would take a filter if required, maybe their parts are generic and the filters are fitted if required.
So from this I was wondering what the groups thought were on the benefits/presence/absence of filters.
I noted the the Acetylene reg had considerable blackening in the inlet stem and slight crustiness on the inner surface. Maybe this contributed to internal contamination. Regarding use the rags are maybe 7-8 years old and I don't use that much gas, bottle change every 1 to 2 years depending on usage, the bottle being medium sized.