Heavy Duty Transformer Breathers

required number of breathers

Breathers to suit 9 to 750 MVA Transformers

  • Description

The failure or malfunction of many transformers or similar equipment can be directly attributed to the lack of proper control of the level of water vapor entering the equipment. It is essential, therefore, that a very low level of humidity is maintained in the airspace of the conservator tank to avoid deterioration in the insulating properties of the cooling medium. Envirotronics High Durability Transformer Breathers provide an economic and efficient means of controlling the level of moisture entering equipment during the change in volume of the cooling medium and/or airspace caused by temperature gradients.

High Durability Transformer Breathers are filled with self-indicating silica gel desiccant which changes color from blue to pink or orange to green as it becomes saturated with water vapor.  Transformer Breathers are designed to enable the quick and easy replacement of the desiccant charge.  When the bottom half of the desiccant is pink or green, the charge should be replaced.  Replacement of either type of silica gel is available in standard 25 kg containers. If a smaller quantity is needed, please contact Envirotronics for repackaging options.

Envirotronics Transformer Breathers are constructed with a tough UV stabilized glass loaded polycarbonate, which is extremely durable. They are fitted with a two-way relief valve mechanism that eliminates all maintenance except when the desiccant needs to be replaced. These Transformer Breathers have a viewing window (there is 180 degree visibility on the small units) to easily determine when the desiccant needs to be replaced.

HIGH DURABILITY TRANSFORMER BREATHERS SELECTION GUIDE

Desiccant Charge in Lbs. (kgs)Part NumberModelMax. Oil
Contents
in Gal. (Liters)
Approx.
Transformer
Rating (MVA)
Max. Air
Space Volume
in Gal. (Liters)
11.02
(5.0)
BL/D6290/01V2998
(11,350)
9634
(2,400)
22.05
(10.0)
BL/D6290/02W5,997
(22,700)
301,268
(4,800)
31.97
(14.5)
BL/D6290/03X8,995
(34,050)
601,915
(7,250)
38.58
(17.5)
BL/D6290/04Y12,007
(45,450)
1002,559
(9,685)
60.19
(27.3)
BL/D6290/05Z18,003
(68,150)
1803,830
(14,500)
Part NumberApprox. Daily
Breathing Rate
in Gal. (Litres)
Max. Air Volume
Before Recharge
in Gal. (Litres)
Approx. Charge
Life in (Days)
Overall Length H in In. (MM)Dimension D in In. (MM)
BL/D6290/0137
(140)
12,007
(45,450)
32014.8
(375)
10.0
(255)
BL/D6290/0274
(280)
24,013
(90,900)
32021.9
(555)
10.0
(255)
BL/D6290/03111
(420)
36,059
(136,500)
32028.9
(735)
10.0
(255)
BL/D6290/04151
(570)
48,026
(181,800)
32019.1
(485)
14.0
(355)
BL/D6290/05222
(840)
72,040
(272,700)
32025.4
(645)
14.0
(355)
Part NumberFemale Pipe Thread SizeCharge Length J in In. (MM)Charge Diameter G in In. (MM)
BL/D6290/013/4″-14 BSPP but 3/4″-14 NPSM will work8.94
(227)
8.15
(207)
BL/D6290/023/4″-14 BSPP but 3/4″-14 NPSM will work16.00
(407)
8.15
(207)
BL/D6290/033/4″-14 BSPP but 3/4″-14 NPSM will work23.10
(407)
8.15
(207)
BL/D6290/041″ BSPP but 1″-11-1/2 NPSM will work13.46
(342)
12.05
(306)
BL/D6290/051″ BSPP but 1″-11-1/2 NPSM will work19.76
(502)
12.05
(306)

The table above should be used for the basic selection of a Transformer Breather.  In order to assess the size of the breather, the air volume above the oil in the conservator tank is the most important factor.  The quantity of oil and the transformer rating is of secondary importance. Transformer Desiccant Breather models V, W and X have a 3/4″ female pipe thread; models Y and Z have a 1″ female pipe thread.

The daily breathing rate is based on the assumption that there are two temperature drops of 8°C per 24 hours.  The breathing volume change, which occurs during the pump start-up, is not taken into consideration.

If your needs exceed what is listed in the table, please contact Envirotronics for our double and triple chamber models.

The typical desiccant fill for Transformer Breathers is 2-5 mm beaded blue indicating silica gelOrange silica gel is also available.  The sight windows on models V, W, X, Y and Z and the double and triple units are manufactured from the same material.

It is important to emphasize that, with the exception of routine inspection to determine the condition of the desiccant, Envirotronics Transformer Breathers are virtually maintenance free.

BL/D6290 Drawing

V, W, X, Y and Z Transformer Desiccant Breather