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Machinery Grouting
Posted: 05 Apr 2010, 11:29
by PERVEZ AKHTAR
We are in the process of installation machinery on Byco Refinery project.We would like to seek guideance in following areas.
- Specification of groute material for pumps , turbines , fans ,blowers and compressors.What maximum permissible groute thickness is allowed.
- We have skid and volute casing whereas pump / motor are removed from skid for preservation purpose.Can we install and groute skid and casing only .Pump/Motor will be installed and aligned after Grouting .Pl comment.
Rgds
Pervez Akhtar
Re: Machinery Grouting
Posted: 05 Apr 2010, 12:11
by fraz
a. Usually for large compressors and turbines epoxy grout is used of 16,000 psi after cleaning of foundation from dust and water. Chock fast is a good grout ,Foss pak is also available in market but there are some observations of cracks in this grout. Although these cracks can be eliminated with injecting the epoxy again (by supplier).
b. For smaller pumps, motors and tubines cementitious grout is used and
1. For grouting a skid > 4ton with cemntitious, you should use 10,000 psi grout ( brand names Congrout 1000 / BB80 / Masterflow / equivalent)
2. For grouting a skid < 4ton with cemntitious, you should use 6,000 psi grout ( brand names Combestra GP 600 etc.)
3. Foundation should be kept wet with water for 24 hours before grouting and should be dryed well with air before grouting.
4. Curing time in summer is 3-5 days and in winter is 8-10 days. Foundation should be kept wet with water for around 10 days after grouting.
5. For saving money on skid > 4ton, you can fill the lower foundation (below the skid) with 10,000 psi grout and remaining area inside the skid can be filled with 6,000 psi grout.
c. Normally the max. height allowed for a grout is 100 mm.
d. According to API standard the alignment of skid is done on the discharge flange of volute casing. Therefore you can do the grouting with no pump and motor and only volute casing on skid. Pump and motor can be aligned later.
Re: Machinery Grouting
Posted: 05 Apr 2010, 12:30
by engr.abrar
Hi Pervez,
1. Specification of grout is based on following parameters:
- Vibration produced by machine.
- Weight.
-Critical machine or non-critical with respect to operation.
If you have a reciprocating pump or high speed centrifugal pump with high unbalanced forces (causing high vibrations) then you must go for the epoxy grout. Otherwise if your pump has less unbalanced forces then you can use cementitious grout. Please note that epoxy grout is 8-10 times costlier then cementitious grout so it is very critical to decide which grout to use.
2. Usually clearance of usually 1 in. to 1 1/2 in. between the foundation and the equipment to be grouted. This is fine when using a high flow-type epoxy grout; however, when using a flowable epoxy grout, you may encounter problems when flowing distance is greater than 2 ft, or when cooler temperatures are encountered. Either you have to use chains to keep the grout flowing to the farthest end or increase the clearance. But, keep one thing in mind that each type of epoxy grout or cementitious grout are made for certain pouring thickness. So you have to select the right grout as per your requirement.
3. Grouting is usually done under skid after installing the pump, motor or any other perpheral which adds weight on skid.
Hope this will answer your query.