Small Bore EXpert training is widely recognized in the oil and gas industry. Having the right training can vastly reduce risks such as personal injury, service downtime or environmental contamination.
Secure, leak-free tube fitting connections don’t happen by chance; there’s a proper procedure that needs to be followed. If you work in the oil and gas, energy or marine industries, it’s important to specify and assemble tube fittings correctly.
Instrumentation twin ferrule fittings are designed for high-pressure applications (such as 6,000psi or above). One ferrule seals the fitting, whilst the other secures it in place.
Parker’s fittings are made from materials including 316 stainless steel, 6Mo and even titanium. They are also heat code (HCT) traceable, so all materials can be traced from the original foundry.
Three steps to making up twin ferrule fittings
There are three steps to making up fittings:
Step one – selecting and specifying tubing
The first step is to make sure your tubing has been correctly selected and prepared. Typically this involves actions such as:
- Checking the tubing is of the correct hardness
- Cutting it square
- Removing any contamination (such as metal filings).
Without following these procedures, there is a risk of leaks or tube blow-outs.
Step two – specifying the fitting
At this stage, it’s important to match the material of the fitting with the material of the tubing, then match the size of the fitting with the tubing.
Material selection is increasingly important today. If the wrong combination of materials is used, there’s a higher risk of galvanic corrosion (where in certain conditions, one material can corrode the other).
The diameter of the tube being used will affect the number of turns to make up the fitting. This information is typically found in a manufacturer’s technical guide, such as Parker catalogue 4190 FMTG.
It’s important to make sure the ferrules are correctly installed within the fitting. To do this, take a piece of tubing and place it into the fitting. Then by removing the nut, you can check the position and orientation of the ferrules.
Step three – assembling the fitting
Now, it’s time to place the fitting into the vice and tighten it securely. When inserting the tube into the fitting, finger-tighten the nut to provide a start position. Mark the start position with a chlorine-free marker (as chlorine can affect the fitting material).
Next, take a suitably sized spanner or wrench and tighten the nut to the recommended number of the turns, as stated in the manufacturer’s manual. Once the correct number of turns has been achieved, remove the fitting from the vice and use an appropriate gap gauge, based on the tube size. (In the video example of SBEX Small Bore EXpert Training, we use a no-go gauge, so you would not expect this to fit in the gap.)
Finally, put the fitting back into the vice, fully undo the nut and remove the tube. Using the gauge, double-check that the ferrules have been set the correct distance from the end of the tube. If there are any errors, start the procedure again with a new tube and new ferrules - trying to adjust ferrules at this stage can lead to tube blow-out so it’s important to maintain safe procedures.
Assuming the ferrule settings are correct, place the tube back into the fitting body and finger-tighten the nut to achieve a start point. Then use a spanner or wrench to take it back to the original position.
By following these steps, you can achieve a secure, leak-free connection first time, every time.
This post and video offer a taster to SBEX training. If you’re ready to take the fully certified SBEX training, Parker’s courses combine theory and practical knowledge.
This includes certificated Small Bore EXpert (SBEX) training plus hydraulic hose assembly, steel tube fitting assembly, tube manipulation and thread identification seminars.
Courses run each month and extra dates can be booked according to customer time and location requirements. To get information about available courses or book a date, please click the Safety Training image and register or call in the UK (01926) 317427.
Article contributed by Phil Ingate, a training manager with Parker’s UK sales company, with more than 35 years of hydraulics experience. He regularly provides training to oil and gas, marine and energy professionals.