Black Compression Fittings (.700 OD Tubing)

The colors of compression fittings often indicate the size compatibility of the fitting with specific types of poly tubing. Black is generally used for poly tubing with an outside diameter (OD) of 0.700 inches. Blue usually signifies a fit for poly tubing with an OD of 0.710 inches. This size may sometimes have a blue stripe on the tubing itself.

While replacement is generally preferred, these fittings can be reused as long as they’re still in good condition. After removing the fitting from the tubing, make sure to inspect the fitting for cracks, distortion, worn internal gripping surfaces, or leaks before reinstalling it. If you need to replace the internal locking ring, it may be easier to just use a new fitting.

.700 compression fittings are generally designed for low-pressure drip irrigation systems. Their maximum working pressures may vary, but drip systems commonly use a pressure regulator to reduce incoming water pressure to a suitable level. For higher-pressure applications, consider using more rigid tubes and fittings.

If your fitting is leaking, the first step is to make sure that the tubing is fully inserted into the fitting. The tubing needs to slide past the internal locking ring to seal properly. You should also make sure that the tube’s outside diameter is compatible with your fitting, as tube sizes may vary. Next, check for cracks and wear at the end of the tubing. If necessary, use tubing cutters to make a perfectly straight cut before reinserting it.

Many of our .700 black compression fittings can be installed underground. These fittings are made from a durable plastic and won’t degrade when buried. Burying the tubing and fittings can also protect them from landscaping equipment and foot traffic. Just be sure to run your system to check for leaks before burying the lines, as compression fittings are difficult to adjust once covered.

To remove a compression fitting, you’ll need to use a wrench to loosen the compression nut then unscrew it from the fitting. After the nut is removed, slide off the compression ring. If it's stuck or difficult to remove, feel free to cut it off, as compression rings can be replaced. Once the nut and ring are removed, the pipe should easily slide out of the fitting.