In the dry climate of the Rocky Mountains you really only get a rust bloom like this on your carbon steel when it sees direct contact with water (this new piece of ductwork just saw the first of many rainstorms in its life). However, in humid climates you’ll get this same rust inside of your vessels that aren’t even exposed to rain. That’s why it’s important to put down a coat of primer such as Pennguard HB, Penntrowel Epoxy Primer, or other similar ErgonArmor products as soon as possible after you’ve cleaned and prepped your surface. That’ll ensure you seal it in and are ready for a solid bond between your steel and your vessel lining system.

We’ve been supplying industrial process equipment around the world since 1983. We believe in delivering the highest quality hardware to keep an American industry up and running. Process knowledge is our passion. Most vendors understand their products, but we understand your process and how our products will interact with it. We’re here to help you avoid downtime when downtime isn’t an option. INTEREP was created out of the ashes of the 1980’s oil bust. Our founder, Carl Horecky, swore he’d never put all his eggs in one basket again. From there, INTEREP was born and forged a path to become not only suppliers, but experts. In 2021, we’re excited to continue growing our team of professionals who live for the unique challenges and solutions of unforgiving environments. We’d love to hear from you! Bring us your piping or ducting design challenge today and let us show you why so many industrial facilities trust INTEREP as the experts.

A customer reached out to us with a dilemma. They had a whole duct full of fabric expansion joints that were burning up, and they needed all new ones in less than 4 weeks. What’s weird is the flue gas is normally only 300F. However, they sometimes bypass 1000F gas into it and ALL of the gas that goes through this duct is high in sulfur. Instead of providing a new expansion joint with more insulation, we decided to calculate the minimum allowable amount of insulation based on their excursion durations and temperatures, put in all stainless flow-liners, hardware, and frames, and topped it off with silicone gaskets to help get the PTFE belt as watertight (or acid tight) as we could. Over-insulating the internal cavity pillow would cause sulfuric acid condensation inside the expansion joint (between the belt and pillow). Is it going to build up acid on cold days still? Probably. Is it going to keep the plant up and running without leaving gaping holes in their ductwork? Definitely.

When somebody decides to replace a failed expansion joint with an unlike expansion joint laying in the boneyard, things will eventually go wrong. INTEREP was able to right this wrong by redesigning a new metal bellows and spring support to allow for many more years of worry-free operation. Call us if you’re ever in a sticky situation – we’ll bail you out.

An oil refinery had blown out their bellows by hydro testing their sulfur unit at pressures that exceeded what the system was designed to handle. INTEREP upgraded the poorly designed expansion joint to a much sturdier, lasting design, and this was the end result. INTEREP designs for longevity and serviceability. Give us a call and we’ll deliver Peace of Mind to your operations.

Installing Expansion joints against pipe with stub ends and metal rings that back up against our rubber flange causes problems with sealing. The best system with pipe like this is to add an HDPE Flange Ring that lays against the stub end and then attach the rubber flange to the full face HDPE flange.

This reverse air baghouse expansion joint was made of EPDM operating at above 400F, the EPDM got brittle and ended up adhering itself to the duct and cracking across the bottom – filling the penthouse with SO2 gas. Our team retrofitted the expansion joint with one made of PTFE (Teflon) that could handle the temperature. Reverse air ducts can be hard on equipment because they switch from positive to negative pressure, so you want an expansion joint belt with no excess width in it, or it will get sucked into the duct during pressure changes and wear the edges of the belt out.

What happens when you heat liquid carbon dioxide? #Cardox – high-pressure gas (>40,000psi) Cement plants use it to clear plugged preheater tower meal-pipes. This metal bellows was too close to a Cardox charge (top left) which destroyed the refractory meal-pipe lining & damaged the expansion joint. The refractory was repaired with Blu Ram (phos-bonded mullite) and we manufactured a new bolt-in metal bellows expansion joint which slides into the meal-pipe (bottom left & right).
