BACKGROUND

The present disclosure relates to abrasive blasting systems, and more particularly, to a pop-up seal for an abrasive blasting system.

Blasting systems in the surface preparation industry generally use dry, wet, slurry, vapor abrasive, or ultra-high pressure water blast technologies to remove dirt, paint, or rust from a substrate. Vapor blast systems use a mixture of air, water, and an abrasive media—such as garnet—to provide the desired surface treatment. Vapor blast systems often include a pump and a pressure vessel containing an abrasive blast media having a density greater than water. Pumping water to the pressure pot pressurizes it and allows abrasive blast media and water to mix. The pressurized blast media and water mixture is then plumbed into a conduit of a high flowing air stream to mix the two streams before expelling the mixture from a hose and blast nozzle.

In vapor abrasive blasting systems, it is important that the pressure pot of the blasting system be purged of air prior to commencement of the blasting operation. Pressurized water forces a slurry out of the pressure pot, into a piping system, and finally into a mixing point where the wet slurry is mixed with compressed air. Fluctuations in flow of pressure in either the slurry or pressurized gas result in inconsistent behavior of the vapor abrasive blasting system and ultimately lead to an uncontrollable or inefficient blasting process. Air entrapment underneath a pop-up seal of the pressure pot or pressure vessel is a contributing factor to instability of vapor abrasive blasting systems. Existing pop-up seals are cast which have pockets that trap air and can cause rust to form. Presence of through holes in existing pop-up seals causes fluid leaks through the seal.

SUMMARY

A vapor blast system includes a pressure pot with an upper end and a main body, a fill inlet attached to the upper end of the pressure pot, and a seal assembly disposed in the pressure pot. The seal assembly is configured to control a flow of a fluid between the pressure pot and the fill inlet. The seal assembly includes a pop-up seal, a pipe, and a spring. The pop-up seal comprises an upper surface, a lower surface disposed opposite the upper surface, a blind hole disposed in the upper surface, a bore disposed in the lower surface, and a centerline axis disposed through a center of the pop-up seal. The pipe is attached to a lower surface of the pop-up seal, wherein a portion of the pipe is received by the bore. The spring is disposed in the bore and engaged with the pipe.

A method of making a seal assembly for use in a pressure pot of a vapor deposition system includes machining a pop-up seal. The pop-up seal includes a centerline axis, a body, a blind hole, an upper surface, and a lower surface. The blind hole is disposed in the body and includes a cutout. The upper surface includes a first radially inner portion comprising a first average slope relative to the centerline axis of the pop-up seal and a second radially outer portion comprising a second average slope relative to the centerline axis of the pop-up seal. The second average slope is greater than the first average slope. The lower surface includes a frustoconical configuration with an upward slope relative to the centerline axis of the pop-up seal. The upper surface of the pop-up seal is coated with a rubber coating.

A seal assembly includes a pop-up seal (formed of machined aluminum, brass, or steel), a rubber coating, a pipe attached to the pop-up seal, and a spring. The pop-up seal includes a body, an upper surface, a lower surface disposed opposite the upper surface, a blind hole disposed in the upper surface, a bore disposed in the lower surface, and a centerline axis disposed through a center of the pop-up seal. The blind hole includes a cutout extending into a portion of the pop-up seal. The rubber coating is disposed on the upper surface of the pop-up seal. A portion of the pipe extends into the bore. The spring is disposed in the bore and is engaged with the pipe.

