can we use the galvanised bolts in the underground flanges of GRE,directly buried in contact with

[ismail06]

HI EVERYONE

I would like to have some feed back about on the galvanised bolts in the underground flanges of GRE , for firefighting network new project, directly buried and in contact with soil )may be subject to corrosion or not.

I am just to see the necessity to protect these bolts by some type of coating because they will be in direct contact with soil and to avoid the corrosion potential problem.

Many thanks for your helpfull

Regards

From Reggane project

 

[mk3223]

Depending on the soil type and condition, such as moisture, pH level, chloride, etc., the service life of the galvanized steel depends on the coating thickness. Refer to the AGA link below.

https://www.galvanizeit.org/hot-dip-galvanizing/how-long-does-hdg-last/in-soil

 

[bimr]

Pay particular attention to the need for stainless steel bolts in buried and submerged valves and valve exposed to H2S atmospheres. In some soils and waters, galvanized steel bolts and nuts (AST A307) corrode readily. Therefore, type 304 or 316 stainless bolts (ASTM A193, Grade BS or BS and nuts (ASTM Al94, Grade 8 or SM) may be required.

Many water utilities have standardized with stainless steel for buried water mains. All bolt-up sets (nuts, bolts and washers) and tie rods for buried valves and fittings are stainless steel.