BALANCED PRESSURE STEAM TRAPS


Balanced Pressure Thermostatic Steam Traps are equipped with a capsule element, which controls the discharge of condensate depending on the temperature. The capsule contains a special liquid, whose saturation temperature at a given pressure is always lower than that of the water. It ensures a very accurate functioning of the steam trap and is self-adjusting.
The discharge characteristic follows the saturation curve independent from pressure changes and the condensate load.

Series D MIYAWAKI steam traps can be delivered with 3 different capsule types:
  • Types H & C discharge hot condensate at approximately 5°C (9°F) below saturation temperature;
  • Type L discharges hot condensate at approximately 15°C (27°F) below saturation temperature.

Operating principle


Model DC1

Specification

Model
Available
Sizes
Available
Connections
Maximum
Operating
Pressure
MPa
(psig)
Maximum
Operating
Temperature
°C
(°F)
Body and
Cover Material
Download
DL1
1/2"-1"
Screwed
Rc & NPT
2,1
(305)
220
(428)
Stainless Steel

DF1
1/2" – 1"
Screwed
Rc & NPT
Socket weld
JIS, ASME, DIN
Flanged
JIS, ASME, DIN
2,1
(305)
235
(455)
Forged Steel

DV1 with bypass
1/2" – 3/4"
Screwed
Rc & NPT
1,0
(145)
184
(363)
Stainless Steel

DC1
1/2" – 1"
Screwed
Rc, NPT
Flanged
JIS, ASME, DIN
2,1
(305)
220
(428)
Stainless Steel

DC2R
1/2" male x 1/2" female
Screwed
Rc, NPT
1,6
(230)
220
(428)
Stainless Steel

DX1
38 mm
Tri-Clamp
0,5
(73)
160
(320)
Stainless Steel

Features

  • Excellent air venting characteristics at start-up and during operation;
  • Insensitive to waterhammer;
  • The operation will not be influenced by back pressure;
  • At time of non-operation self-draining;
  • No steam loss throughout its operating range;
  • All traps equipped with integral strainers;
  • Can be installed both horizontally and vertically;
  • Easy in-line inspection and maintenance;
  • Lightweight, compact design.

Suitable for:

Light to medium condensate loads: steam tracing, steam main drips, small heat exchangers, unit heaters, steam heating coils and many other applications in the petrochemical, chemical, textile, food, pharmaceutical and other industries.

Operating principle:

cold-condensate cold condensate hot-condensate hot condensate steam steam



d1

d2

d3

d4



Upon start-up in the presence of cold condensate, the capsule element is contracted and the valve plate has moved away from the seat. The wide open valve discharges condensate and air rapidly.


As the temperature inside the trap increases, the capsule element will start to expand, moving the valve plate toward the seat.


Just before the condensate reaches saturation temperature, the valve plate will close the seat completely. Steam can not enter the trap, ensuring zero steam loss.


As the temperature inside the trap decreases, the capsule element moves away from the seat and the condensate will be discharged. During normal operation steps 3 and 4 will repeat continuously.

Operating principle of DV1 when using the bypass valve:


dv


dv



When the handle is turned in the direction indicated by the BLOW arrow on the nameplate (counterclockwise), the bypass valve will open, a bypass circuit will be formed inside the trap, and a large volume of air and condensate can be discharged quickly. Scale that has accumulated in the screen can also be blown out.
When the bypass valve is closed, the type DV1 will operate as a normal steam trap (see above operating principle).