Thermal Disc Steam Traps

Operation

Tunstall Corporation produces a full line of Thermal-Disc™ Steam Traps. Available in 3/8″, 1/2″, 3/4″ and 1″ NPT connections, all the internal parts are stainless steel for long service life.

The Tunstall Thermal-Disc™ operates using Bernoulli’s Theorem; as condensate enters the Thermal-Disc™ Trap, it lifts the thermal disc and discharges through outlet ports. Multiple outlet ports assure that the lift of the disc is parallel to the seat for efficient operation. Once the condensate reaches its flash point, the pressure on the top of the disc increases, due to higher velocity steam, causing the disc to snap closed. As the steam above the disc condenses, pressure above the disc will lower, and allow the disc to lift again and repeat the process.

Features

  • In-Line Connection
  • Integral Strainer
  • Compact Size
  • High Strength Stainless Steel Construction
  • Low Maintenance (Only one moving part)
  • Can be installed Vertically for “Freeze Proof” installation

Applications

  • Steam Main Drainage
  • High Pressure Drips
  • Tracer Lines
  • Process Equipment
  • Laundry Equipment
  • Kitchen Equipment
  • Superheated Steam applications
  • Outdoor installations subject to freezing

Construction

Materials of Construction
Body Stainless Steel Casting ASTM A743
Cap Stainless Steel AISI 420
Disc Stainless Steel AISI 420
Strainer Screen Stainless Steel AISI 420
Strainer Cap Stainless Steel AISI 420

Specifications

Pressure/Temperature Rating
PMA – Max. Allowable Pressure: 600 psi
TMA – Max. Allowable Temperature: 800° F
PMO – Max. Operating Pressure: 600 psi
TMO – Max. Operating Temperature: 800° F

Dimensions and Weights

Model Size A B C Weight
TA-TD-38 3/8″ 3 1.75 2.5 1.6
TA-TD-50 1/2″ 3 1.75 2.5 1.8
TA-TD-75 3/4″ 3 1.75 3 2.4
TA-TD-100 1″ 3 1.75 3 2.6

Note: Dimensions in inches & Weights in pounds

Capacities – lbs. of condensate/hr

Inlet (psig) TA-TD-38 TA-TD-50 TA-TD-75 TA-TD-100
3.5 180 300 415 650
5 185 315 430 680
10 190 350 475 740
15 195 380 520 815
20 200 415 565 885
25 215 440 610 940
30 220 470 650 1000
40 230 515 720 1080
50 250 580 825 1225
75 310 710 1020 1500
100 375 825 1185 1800
150 500 1020 1480 2215
200 620 1165 1710 2625
250 710 1300 1950 2935
300 800 1440 2110 3300
350 825 1565 2265 3600
400 900 1670 2490 3875
450 1070 1775 2625 4120
500 1120 1880 2780 4350
550 1185 1960 2985 4560
600 1290 2060 3140 4840

Note: Max. back pressure should not exceed 80% of the inlet pressure under any conditions of operation, otherwise the trap may not shut.

Installation
Valve installation is typically in the horizontal position as close to the equipment being drained as possible. A 20 mesh strainer is recommended upstream of the trap as is an isolation valve. Piping to and from the trap should be equal to the trap connection (one size larger is acceptable). Body material is not suitable for welding.

Freeze proof installation is achieved by installing the trap vertically, discharging downward. All drains must be pitched towards the trap. Discharge piping must be self-draining.

BULLETIN: Series-TA-TD-0814 – Thermal-Disc Steam Traps – Series TA-TD