Washers on manway flange
Washers on manway flange
(OP)
Dear all,
I have a vessel fabricator who supplys zinc galvalized washers for bolting on carbon steel manway flange. I have never seen using washers for manway in the past.
What is the con of using washer ?
I have a vessel fabricator who supplys zinc galvalized washers for bolting on carbon steel manway flange. I have never seen using washers for manway in the past.
What is the con of using washer ?





RE: Washers on manway flange
RE: Washers on manway flange
RE: Washers on manway flange
99.99 % of flange joints at sites, including manways, no washers were ever used. So what is the reason NOT using washers if washers proved to be a good idea ?
RE: Washers on manway flange
RE: Washers on manway flange
RE: Washers on manway flange
RE: Washers on manway flange
RE: Washers on manway flange
"Whom the gods would destroy, they first make mad "
RE: Washers on manway flange
I believe the main reason is that the use of washers is OPTIONAL. If the Codes mandated the use of washers, 100% of flange joints at sites will have washers. [bigsmile]
Dean8573 raises a good point regarding corrosion. A similar scenario will also occur for painted flanges, especially when there is excessive paint thickness under the washers. Over time, the paint will deteriorate.
RE: Washers on manway flange
The idea that the washer helps spread the load is fairly ludicrous when you look at the relative thickness of the washer compared to the nut for most pressure flanges. If used they need to be no larger than the outer diameter of the nut and made from hardened material.
Basically washers are something which can be abused with use of non hardened material very difficult to verify on site and the safest way to avoid this is simply to avoid using them in the first place.
If you search a bit more on this site you will find this debated many times before with some fairly different views...
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way