Temperature Effects on Pressure Rating:

The temperature of the gland will greatly affect Its maximum safe operating pressures. For example, a stainless steel gland which has a pressure rating of 6,000 PSI at 68°F has a pressure rating of 5,500 PSI at 500°F, 4,200 PSI at 1000°F, 2,500 PSI at 1500°F and only 1,500 PSI at 2000°F. A brass gland is generally not advised for use above 500°F. At 500°F, the maximum pressure rating of brass glands falls to about 1/10 the pressure rating at 68°F. Copper electrodes are not recommended above 500°F. At 500°F, the pressure rating of copper electrodes falls to about 1/15 the pressure rating at 68°F.

Temperature Effects on Electrodes: Since each metal has a positive coefficient of resistivity as the temperature of the electrode increases, its resistance also increases, thus making it a poorer conductor. Example: If a given length of copper wire has a resistance value of 1.00 ohms at 32°F, it will have a value of 1.43 ohms at 212°F, 2.3 ohms at 575°F and 2.75 ohms at 750°F. Because of the tapered principle in NANMAC electrodes, the diameter of the electrode in the hot zone is always larger than that In the cold zone- Thus, the increase in resistance of the electrode due to temperature is offset by its large diameter which produces a low initial resistance. The overall result is an electrode whose current carrying capacity in the hot zone Is the same as that portion of the electrode in the cold zone.

NOTE: The information contained here is meant as a guide only. Nanmac strongly recommends that you perform your own calculations on various current, pressure and temperature ratings based upon your own application. Again, this information is offered as a guide only.

OR-SERIES ELECTRODE GLAND
O-Ring Type

The OR Series electrode gland has a gland body with straight threads and an 0-ring external seal. The units are recommended for low vacuum applications (5 x 10-6 mm hg) or low pressure ap- applications The upper temperature limit is 450°F. limited by the rubber 0-ring. (The upper- temperature limit can be increased to 1000°F by replacing the rubber 0-ring with a metal 0-ring).


A-SERIES ELECTRODE GLAND
NPT Thread

The A-Series Electrode Gland contains National Pipe Threads on the gland body. These units are ideal for applications from atmospheric pressures to 5,000 or temperatures to 500'F.


HP-SERIES ELECTRODE GLAND
Conical Seal

The HP-Series Electrode Gland has an external metal-to-metal seal formed by tightening the gland nut into the test wall. The 59° conical section of the gland is designed to mate with a 60° conical section in the wall of the test chamber. These units can be used from low vacuum 15 x 10-6 mm Hg to 10,000 PSI The maximum temperature range of these units is 500°F, The HP-Series electrode glands are furnished with stainless steel glands. Brass is not used because of its low pressure range. The HP units come with copper or stainless steel electrodes.