Moeller ? As in the guys who make a lot of plastic gas tanks?
Brand seems of limited importance to me. From the picture it looks like a welded aluminum tank, or possibly stainless. It looks like a bung is welded into the tank, possibly tapered pipe thread. Often fuel fittings that are screwed together have some sort of fuel rated pipe dope on them. Some paste dopes are non hardening, others harden like a rock & become difficult to remove. Dissimilar metal corrosion also causes issues sometimes. Some aluminum tanks & aluminum fuel filter housings come with aluminum fittings now, to prevent that issue.
Bottom line, you can probably unscrew it, but there is no guarantee. I see no evidence of salt build up, so I see no need to start with warm soapy water, but a few drops of penetrating oil, about a half hour before you start trying to turn it, may be helpful.
Keep your eyes open for a check valve. They get hidden in strange places sometimes & can plug up solid.
Brand seems of limited importance to me. From the picture it looks like a welded aluminum tank, or possibly stainless. It looks like a bung is welded into the tank, possibly tapered pipe thread. Often fuel fittings that are screwed together have some sort of fuel rated pipe dope on them. Some paste dopes are non hardening, others harden like a rock & become difficult to remove. Dissimilar metal corrosion also causes issues sometimes. Some aluminum tanks & aluminum fuel filter housings come with aluminum fittings now, to prevent that issue.
Bottom line, you can probably unscrew it, but there is no guarantee. I see no evidence of salt build up, so I see no need to start with warm soapy water, but a few drops of penetrating oil, about a half hour before you start trying to turn it, may be helpful.
Keep your eyes open for a check valve. They get hidden in strange places sometimes & can plug up solid.
