HRSG penetration seals come in all shapes and sizes and are the most common expansion joint on your units. We have installed seals on almost every type of HRSG manufacturer, including Nooter, Deltak, Voight, Nimms, Doosan, and Alstom to name a few. Our seals are fabricated with a foundation of a thermal barrier to reject gas flow from entering the seals, a high temperature flexible material to function every cycle under 140°F, and a clamping backing bar to keep the fabric sealed to the frame. We have been installing seals for over 9 years with constant progress and improvements to making them last longer under the harsh environments they endure. Our engineering team has a small R&D lab that is constantly testing new materials and arrangements to help maximize their lifespans.
One of the common misconceptions about penetration seals is they are all the same; however, each seal requires individual engineering to maximize effectiveness. IAFD examines each seal’s location on the HRSG, the temperature at the location, the expansion or contraction the seal endures, any vibration or lateral movement, and finally, its proximity to items around it. With this data, we model the ideal seal to withstand that environment. It doesn’t matter what configuration your seals are in, we can retrofit and design a RAP™ seal to fit the application!
With each group of seals being unique to that machine and section, every RAP™ seal is custom made for you. In some situations, we have made casing alterations to receive new frame work, as pictured below.
On the HRSG’s there are (3) locations for the penetration seals: the roof, the side walls, and the floor of the unit. Each location has one of (3) style seals: mechanical slip (packing gland), metal bellow, or fabric. All of IAFD’s seals are fabric, and we can replace mechanical slip or metal bellow styles. The following images show extensive damages to a roof seal and the repairs made by IAFD.
Our replacement seals include specific insulation packing around the seals as well as a new high temperature belt over the frames. Here are a few completion photos:
Many units have side wall penetration seals near the top and bottom of the unit. In most cases, they tend to be a metal bellow type. We have a kit that can completely replace the bellow with a new metal frame and fabric. In order to replace a metal bellow like in kind, it requires the pipe to be cut to slip the bellow over or a clam shell design which is extremely difficult to weld together. Our new frame work attaches to the HRSG casing and the existing tab on the pipe. This process is quick and requires no pipe cutting, leaving the fabric material the only part for future maintenance. If you calculate the replacement fees for a bellow like in kind, you could replace the fabric on the seal (3) times to one!
One of the most common types of seal is the lower penetration. With a unit top hung, these seals can see large expansion growth, some over 9″ downwards. IAFD has created the RAP™ Seal to solve the heat, movement, and leaking problems for these conditions. These cover failed bellows, packing glands, or other fabric seals. The images show metal bellow and fabric seals that IAFD replaced with new seals.
The following are images of failed seals:
After installation of RAP™ Seals:
Our seals will handle the long summer runs or the vicious cycles that some plants demand. There is a double layer sealing technology that helps increase a gas tight barrier to the outside environment. If you have a seal that always gives you trouble, the RAP™ Seal is your solution.