For Heat Resistant Silicone based Paint application to protect Pipings supposed to operate above 300C a near white metal ( SA 2 1/2 or NACE 1 ) surface preparation is a MUST and post application of Paint a judicious Heat Curing is a mandatory requirement. These are required to generate reliable substaret/Paint bonding and to generate hardness of paint. It is a call for long back that it a running Plant the above 2 excericise is really difficult or rather impractical . It has been heard that few renowned international companies has manufactured and/or Pilot trialed some HR paint applicable above 300C withoput blast cleaning and without traditional heat curing. Forum expertise is requested to share their experience if any in this regard please with their success and failure rate. regards

Debasis, We have applied HR Silicone based paint in high temp lines successfully. Lines were operating close to 450 deg cent in synthesis gas service and in Superheated Steam lines close of 550 deg cent and in Urea plant piping operating around 250 deg cent only after blast cleaning to SA 2.5 or above and in cold Room Temp conditions. Curing for the two-pack HR silicone paint had to be done gradually as per then available manufacturer's standard practice of curing and adhesion strength for use at this temperature in the above pipelines. I am not sure if HR silicone based paint can be applied in existing operating conditions at 300 deg cent without proper surface preparations and how good would be the adhesion and strength of the HR silicone paint in such usage. Can some one guarantee it would be free from porous films and it would be tight and cured properly in such application without proper surface preparation? How the two pack substrate film would have good adherence and strength in such application? Even if applied, i am not sure if the adhesion would be good and also the curing needed for HR silicone based paint would be perfect to give enough surface bonding and surface adhesion when applied in hot conditions. Second for application in a hot condition at 300 deg cent, i am not sure if brush application is possible other than spray application. If spray applied, how much is the loss during application in a hot line and vapor generated ? If some forum members have experience or if some manufacturers have developed techniques for hot application at 300 deg cent of HR silicone paint for high temperature line (i mean "on-line" application) it would be interesting information to all. Hope this helps C.V.Srinivasan Nishi Engineers Pvt Ltd India Nov 20, 2007 E-mail: nishi@vsnl.com >First of all let me know why you want to paint the pipe >operating at higher temperature and for what purpose?Is it >internally lined pipe or underground drainage pipe operating >at higher temperture?Please clarify. > >regards,