ASTM D3305-94(2005)

Standard Practice for Sampling Small Gas Volume in a Transformer (Withdrawn 2014)

SIGNIFICANCE AND USE
Gases may be formed in oil-filled electrical equipment as a result of faults. The type of fault and its severity may often be inferred from the composition of the gases.
Gas samples are taken from transformer gas spaces or from gas-collector relays in order that the composition of the gas sample may be determined.
In nitrogen-blanketed transformers, the gases generated by a fault will partition between the gaseous and liquid phases. On transformers with gas-collector relays, gas in the form of bubbles may collect in a gas-collector relay and provide a means to obtain a gas sample for analysis.
Do not draw samples from an energized instrument transformer.
SCOPE
1.1 This practice covers the sampling of gas from a transformer gas space or from a gas-collector relay where the volume of gas available is small and will not permit the use of Practice D 2759.
1.2 This practice covers sampling, using a gas-tight syringe as the sampling apparatus and container.
1.3 If the apparatus to be sampled is found to be under a negative pressure, the apparatus pressure should be raised by the addition of nitrogen gas until a positive pressure is obtained.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This practice covers the sampling of gas from a transformer gas space or from a gas-collector relay where the volume of gas available is small and will not permit the use of Practice D2759.
Formerly under the jurisdiction of Committee D27 on Electrical Insulating Liquids and Gases, this practice was withdrawn in January 2014 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 30-Sep-2005
• Withdrawal Date: 08-Jan-2014
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.07 - Physical Test

Relations

• Replaces: ASTM D3305-94(1999)e1 - Standard Practice for Sampling Small Gas Volume in a Transformer
• Effective Date: 01-Oct-2005

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D3305 − 94(Reapproved 2005)
Standard Practice for
Sampling Small Gas Volume in a Transformer
This standard is issued under the fixed designation D3305; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope bubbles may collect in a gas-collector relay and provide a
means to obtain a gas sample for analysis.
1.1 This practice covers the sampling of gas from a trans-
former gas space or from a gas-collector relay where the
3.4 Do not draw samples from an energized instrument
volume of gas available is small and will not permit the use of
transformer.
Practice D2759.
1.2 This practice covers sampling, using a gas-tight syringe 4. Apparatus
as the sampling apparatus and container.
4.1 Syringe, gastight, 5-mL, with luer loc termination.
1.3 If the apparatus to be sampled is found to be under a
4.2 Stopcock, three-way, plastic.
negative pressure, the apparatus pressure should be raised by
the addition of nitrogen gas until a positive pressure is
4.3 Length of PTFE Tubing, ⁄8 in. inside diameter.
obtained.
1.4 This standard does not purport to address all of the
5. Procedure
safety concerns, if any, associated with its use. It is the
5.1 Connect the plastic stopcock to the plastic tubing.
responsibility of the user of this standard to establish appro-
Connect the other end of tubing to a suitable valved entrance to
priate safety and health practices and determine the applica-
the transformer gas space or gas-collector relay.
bility of regulatory limitations prior to use.
5.2 Open the valve and stopcock so gas space gas can flush
2. Referenced Documents
air from valve, tubing, and stopcock. (The stopcock handle
2.1 ASTM Standards:
points to the closed port, leaving the other two ports in open
D2759 Practice for Sampling Gas from aTransformer Under
communication.)
Positive Pressure
5.3 Connect syringe to the stopcock.
3. Significance and Use
5.4 Turn the stopcock handle to allow gas from the gas
3.1 Gases may be formed in oil-filled electrical equipment
space to enter the syringe, taking care that gas pressure does
as a result of faults. The type of fault and its severity may often
not eject the plunger completely.
be inferred from the composition of the gases.
5.5 Turn the stopcock so gas can be expelled from the
3.2 Gas samples are taken from transformer gas spaces or
syringe through the exhaust port of stopcock by pushing
from gas-collector relays in order that the composition of the
plunger home.
gas sample ma
...