FAST REPAIR OF BUTTERFLY VALVES WITH BELZONA ELASTOMERS RETURNS VESSEL TO SERVICE ON TIME

KHIA ID: 7754
Industry: Marine (MRNE)
Application: VPF-Valves, Pipes and Fittings (VPF)
Substrate: Steel and existing rubber boot
Customer Location: Oregon, USA
Application Date: September 3, 2018
Products:

Belzona 2121 (D&A Hi-Coat Elastomer)

Belzona 2911 (Elastomer QD Conditioner)


Problem: Two valves were damaged as the rubber boot that provided the sealing surface had suffered damage. One appeared to be damaged by debris that was in the way while the valve was closed removing a large piece of rubber material. The other valve was damaged at the seating area probably during installation.
 
Photograph Descriptions

1. The Customer was excited to use Belzona to complete the repair.

2. Valve 1 with a large piece of rubber boot missing after surface preperation.

3. Valve 2 with damage on the seating area after surface preparation.

4. Repaired valves.

Application Situation
Two butterfly valves that control the flow of seawater in a vessel. The valves needed to be repaired to return the vessel to water on time. 
 
Application Method
A modified version of Belzona System Leaflet VPF-3 was used to repair the valve lining. Loose material was removed and rubber substrate was undercut to avoid a feathered edge. Application area was thoroughly degreased to remove contamination. Steel substrate was ground and rubber substrate was abraded with roughening brush to create a surface profile for Belzona 2121 (an ABS approived product) to achieve a mechanical bond.  The surface was then conditioned with a light coat of Belzona 2911 and allowed to cure. The areas of concern were then masked off and then Belzona 2121 was poured into place. The masking tape was removed immediately and the product was left to cure. After the product had cured the repair areas were machined back to tolerance.
 
Belzona Facts
New boots were ordered for the valves but upon receiving them the boots did not fit. Due to a holiday weekened the Customer chose a Belzona solution as the product and technical assistance were available on short notice. After the product was cured the valves were hydro tested to ensure the valves would hold pressure and they passed the test.