DHW Tank Lining Specs Cement lining 1

[ChiliPipe]

Hi all,
Can anyone share info, specs or recommendations for Cement Lining Domestic Hot Water Tanks? i.e. procedure, materials, etc.
Storage tank is a 60"x120" Vertical tank with 12"x16" manhole access.
Thanks,

 

[SteveWag]

Check this out:

http://hansontank.us/cement-lining-specs.html

Steve

 

[ChiliPipe]

I found this sample on-line that wwas helpful:

1.0 GENERAL
1.1 SHOP DRAWINGS AND PRODUCT DATA
i. Submit shop drawings and product data for following:
a. Tank liner material to be used, with CSA certificate of the product (including the qualifier
"Drinking Water" and "NSF/ANSI-61" below the CSA mark), file # certification, and a
manufacturer's certificate of approved applicator.
b. Sacrificial anode

1.2 INSPECTION FINDINGS
i. Submit written report on condition of existing tank, with interior photos. Electronic photos are
acceptable
ii. Submit interior photos after the tank has been relined and the lining has cured. Electronic photos are
acceptable.


2.0 PRODUCTS
2.1 TANK LINING MATERIAL
i. Line tank with a minimum thickness of 5/8" using CSA certified hydraulic cement lining material, Class
Number 6861-05, Class description: Barrier materials-NSF/ANSI-61 Section 5-Certified to
NSF/ANSI-61 designed specifically for Potable Water under (Drinking Water Systems Components
Health-Effects).
ii. Acceptable Material: “Alkrete” Potable Tankliner

2.2 MAGNESIUM SACRIFICIAL ANODES
i. As recommended by tank manufacturer.

2.3 GASKETS
i. As recommended by tank manufacturer.

3.0 EXECUTION
3.1 PREPARATION
i. Ensure that alternate DHW service is adequate (if available).
ii. Isolate and drain the tank.
iii. Remove the heating bundle or elements from the vessel if either are present.
iv. Perform a general internal visual inspection to determine corrosion activity and tank integrity.
v. Clean tank surfaces. Scrape and remove all decayed and loose particles and loose rust in preparation
for new lining.
vi. Using standard hand tools, remove any loosely bonded contaminants.
vii. Using a mechanical chipper hammer, remove old lining, 2" around all nozzles, man-way ring/ collar and tube bundle collar down to the original steel.
viii. Visually inspect tank walls, inlets, outlets, supports, etc.
ix. Replace existing manway cover with a new 304 stainless-steel plated manway cover.

3.2 APPLICATION OF LINING AND REPLACEMENT OF AUXILIARIES
i. Using a hand trowel, apply two coats of lining material, approx 5/16" each coat, working to a final
thickness of 5/8".
ii. Replace magnesium sacrificial anodes.
iii. Leave tank empty with access door closed. Seal tank and leave empty to cure for a minimum of 12
hours.

iv. Inspect tank the following day to ensure proper curing.
v. Replace all gaskets exposed by the Work. Put man-way covers back in position. Replace high-
temperature manhole/heating bundle gaskets with new and reinsert heating bundle. (if present)

3.3 FINISH
i. After curing period, carefully inspect the new lining to ensure that it is fully cured to full strength. Notify
the Engineer of any concerns.
ii. Fill tank with cool potable water.
iii. Allow tank to remain filled with cool potable water for 12 hours, or as recommended by
the coating manufacturer, before returning tank into service
iv. All work that is required to be performed by a licensed plumber, welder shall be the responsibility of
the contractor (i.e. replacing gaskets, draining/refilling systems, cooling tanks, weld repairs
v. Return tank to service, examining for leaks around man-way covers. Correct as necessary.
vi. Forward an installation quality checklist c/w pictures to the Engineer at the completion of the project.
vii.
viii.



Also Note:

• Hot water tank, internal maintenance is considered a confined space entry and proper confined
space training / certification is required for all crew members on the jobsite.
• The Ministry of Environment (MOE) ref: Safe Drinking Water Act, 2002 O. Reg. 170/03 – Drinking Water Systems, states that “All chemicals & materials used in the operation of the drinking water system that come into contact with water within the system shall meet all applicable standards set by both the American Water Works Association (AWWA) and the American National Standards Institute (ANSI) safety criteria standards NSF/60 and NSF/61.”

 

[waterpipe]

There are different AWWA standards available for cement mortar lining of pipes but I haven't heart about cement lining of a water tank. these standards (C205, C602)will give an insight to some requirements for thickness, material, etc.

Have you considered epoxy coatings that are certified for drinkable water? AWWA covers water tanks with epoxy interior lining in its standards. epoxy is so common for coating (steel)water tanks.