Definition
Ring Type joints are made using a Ring Type gasket and Ring Type joint flange. The RTJ flange has a groove on its face. The RTJ gasket fitted into this groove. The bolts are tightened, and this compresses the gasket. The gasket will fill in the gap and so create a very strong metal on a metal seal.
While these may have raised faces, the faces are to ensure easier accessibility rather than better pressure containment.
The RTJ is a relatively simple join. Just line up the gasket and ensure that it fits into the groove with dual sealing surfaces. Once that has been done, it’s a simple enough matter – the ring will automatically centre itself as you tighten the bolts.
Usage
These advantages of these kinds of joints are:
- They are extremely simple to execute, as long as you position them correctly to start off with, sealing the join is simple.
- A very strong seal is created. This seal will stand up to high heat and high pressure.
- You can choose from a range of different metals when it comes to the material the gasket is made of. You can choose a stronger metal in those situations where more demand is placed on the seal. You can also choose the metal that is most resistant to corrosion.
- Because the join is metal on metal, the seal will last longer and resist the effects of chemicals passing through it well.
- The sealing pressure increases as the pressure used during the process increases. This makes the joint capable of handling not only high pressure but fluctuation pressure as well.
The disadvantages of these kinds of joints are:
- Moisture and dirt can build up in the groove of the face before it is sealed. This could lead to damage to the sealing surfaces. This, in turn, could make the join more likely to leak.
- If you want a strong seal, you have to be sure to align the gasket properly. They have to stay in alignment throughout the whole process cycle. This could become an issue of the metals you are joining are not the same. Say, for example, one metal expands more than the other when heated up. This could cause a misalignment of the seal and potential leaks.
This kind of join is ideal for high temperature and high-pressure situations where a really strong seal is required. Metallic gaskets do last better when it comes to corrosive chemicals than other types. This makes this an ideal join for chemical processing plants.
Currently, it is widely used in petrochemical plants, on oil drilling platforms and in oil refineries as well. It is ideal in industries where:
- Corrosive chemicals are used.
- Temperatures exceed 427° Centigrade.
- Fluctuating pressures or high pressures up to 20 000 PSI.
- It is easy to carry out maintenance on the joint. If it is regularly cleaned, it will withstand corrosion for a lot longer.
In general, choosing the right metal for the gasket, and correct flange type will make this a useful join for most industrial processing applications.
Read the Properties of RTJs here.
