Use this threaded adaptor from RS PRO to connect pneumatic tubing at 90-degree angles. It has an elbow design, which means it's suitable for making angled connections.
The fitting has a threaded connection at one end that's designed to screw onto the matching threads on the length of conduit it's being joined with. It has a push-in connection at the other end, which you can quickly connect to tubing with a simple push for an airtight join. The body of the fitting is made from high-strength POM thermoplastic (polyoxymethylene), which makes it extremely rigid and tough. As this material has a high dimensional stability, this adaptor won't bend or distort under pressure. The thread is made from nickel-plated brass, which is resistant to corrosion.
This fitting is sold in packs of 10. It's been tested by engineers for quality and comes with a 3-year warranty for peace of mind.