Where is the best place to use a Double Seal Manhole Cover and Frame?
Question:I'm currently working towards an MOL learning course, and although I'm fairly sure I know the answer, I'm just after a little bit more clarification.
Answers:
the best place for this type of cover is internally..that is inside a building ..they are designed to prevent smells from escaping ..it is normal to put a bit of grease inside one of the frame seals to create an airtight seal ...majority of these covers all so have screw fixings on the lid
This one seems a bit obvious, even for me. You need not install a manhole cover and frame except where you need a manhole for access.
OK, it is a bit obvious to say you need a manhole where you need access but you need a double seal manhole cover and frame where you want a higher level of sealing for gas. Might be flammable gas / vapours or just smelly gas. A simple manhole may provide structural integrity but leaking gas may be a safety hazard or just a nuisance.
Because its a "double" seal cover and frame, don't you use them inside, in garages for example, when there's a risk of petrol or other explosive mixtures getting into the drain?
I would have thought, inside the property where you would require a gastight seal, and when you cannot obtain the usual water seal because of sloping ground.
Inside
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