Ra or Rz are Units of surface roughness but that's for machining not painting.
In painting, it's microns or mils (25 microns).
Dear Rao:
Press-O-film is the best since it's accurate and records can be supported by tapes, like RT films which are preferred when comparing to UT (after completion of UT one has to trust the report but in RT you can re-check by yourself...!!!).
Regards
Ramin Kondori
QA/QC Manager
IRAN-LNG Preoject
NARDIS ENERGY CO.
Tel.: +98-772-7462189 (Int.171, 172)
Fax: +98-772-7462179
Cell: +98-913-215-0320
Add.(Head office): No.27, 6th St., Seyed Jamalledin-e-Asad Abadi Ave., Tehran, Iran, 1431784891
Add.(Site): NARDIS Office, IRAN-LNG Plant, Kangan-Iran P.O.Box 375(Kangan Post Office)On Sun, Dec 25, 2011 at 9:06 AM, Sharad Sharma <sharad261168@yahoo.in> wrote:
- Hi Rao,
- Pls. refer below
- SA 2
The surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter. Any residual contamination should be firmly adhering.
- SA 2.5
The surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter. The metal has a greyish colour. Any traces of contamination shall be visible only as slight stains in the form of spots or stripes.
- SA 3
The surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter. The blasted surface must have a uniform metallic colour.BLASTING GRADESFollowing is a table giving a clear indication of the comparative blasting grades applicable to national and international standards:BLASTING GRADE COMMON STANDARDS COMPARISON
SSPC steel structures painting council
BS 7079 British standards
SS 05 59 00 Swedish standards
BS 4232
NACE, National Association of Corrosion Engineers
white metal (SP5) SA 3
1st quality
grade 1
near white metal (SP10) SA 2.5
2nd quality
grade 2
commercial finish (SP6) SA 2
3rd quality
grade 3
- RUST GRADES
B Mill scale has begun to flake, rust has started to form
C Mill scale has rusted away or can be scraped off easily and slight pitting has taken place
D Mill scale has rusted away and general pitting can be seen with naked eyeThanks RegardsSharad sharmaSent: Saturday, 24 December 2011 2:37 PM
Subject: RE: [MW:13287] Surface roughness measurement instruments.
--Dear Mr. Rao,In my previous e-mail I mention that SA is roughness but that was wrong. As already mentioned by some other members SA is cleanness of surface after blasting. Unit for roughness is Ra or Rz, two different values, one measures an average roughness the other the maximum roughness, value to be used should be mentioned in the contract / coating specification. Both Ra and Rz will be measured in microns.Met vriendelijke groeten / Best RegardsHerman PieperPieper Quality Support & InspectionPhone: +31 (0)521 380083Fax: +31 (0)84 7539225Cell: +31 (0)6 51691215Van: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] Namens Vasantharao
Verzonden: vrijdag 23 december 2011 13:31
Aan: materials-welding@googlegroups.com
Onderwerp: Re: [MW:13281] Surface roughness measurement instruments.Dear Mr.PieperThank you for your info.Could you pl. give the units for measuring the surface roughness. As per my client spec. it is mentioned as microns only.I think surface appearance after blasting should be SA 2 1/2 or SA 3 and should not be measured in microns.thank youRaoFrom: Pieper QSI <info@pieper-qsi.nl>
To: materials-welding@googlegroups.com
Sent: Friday, 23 December 2011 2:07 PM
Subject: RE: [MW:13277] Surface roughness measurement instruments.
Dear Mr. Rao,Be aware that the microns you mention is not the surface roughness but the coating layer thickness (DFT = Drie Film Thickness).For surface roughness you will have values like SA 2,5 microns or similar and in practice mostly the comparators are used for inspection prior to first layer of coating.After fist coating layer there is no need to measure the roughness anymore.Met vriendelijke groeten / Best RegardsHerman PieperPieper Quality Support & InspectionPhone: +31 (0)521 380083Fax: +31 (0)84 7539225Cell: +31 (0)6 51691215Van: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] Namens jsrisud@gmail.com
Verzonden: donderdag 22 december 2011 14:45
Aan: materials-welding@googlegroups.com
Onderwerp: Re: [MW:13259] Surface roughness measurement instruments.Dear Mr. Rao,
There are portable surface roughness measuring instruments to measure as required.
UK based Rank Taylor Hobson instruments are available in India.
SrinivasanSent from BlackBerry® on Airtel
From: Vasantharao <vasantharao@yahoo.in>Date: Thu, 22 Dec 2011 15:38:40 +0530 (IST)ReplyTo: materials-welding@googlegroups.comSubject: [MW:13256] Surface roughness measurement instruments.Dear Experts,I work as inspection Engineer. When i go for Blasting inspection, contractor provided me profile comparator for surface roughness measurement.Contractor do Grit blasting in the shop.I need to measure surface roughness - 75-100 microns Painting system No#150-75 microns Painting system No#2
QueriesQ 1: Comparator is enough for surface roughness measurements.Q2: Is any other tools available for roughness measurement?.Q3: What is the normal industry practice.
Pl. provide your valuable suggestions as i'm new for painting activities.
Rao.--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
No comments:
Post a Comment