Work Item
ASTM WK49305
New Practice for Determining Compressor Oil Carryover in Compressed Natural Gas Used as a Natural Gas Motor Vehicle Fuel
1. Scope
1.1 This practice is primarily intended for gravimetric determination of compressor oil carryover as aerosols using a filter. There is some vaporization of the lubrication (lube) oil that occurs because of compression of the gas. The oil vapor in compressed natural gas (CNG) can be collected using a tube and quantified. Along with quantification of lube oil, this procedure can quantify solids present in the gas. The solids can be separated during analysis; however, the measurement of solids adds complexity to along with additional time in performing the practice. In most cases, solids have minimal impact on the lube oil carryover rate and are not determined separately in this practice. This practice can be applied to other gaseous samples requiring determination of compressor oil carryover provided the users data quality objectives are satisfied. 1.2 This practice using filters is applicable to analysis of compressor or lube oil carryover as a liquid. This method using a tube is applicable to analysis of compressor or lube oil carryover as a vapor and liquid in CNG present at 1 to 500 mg/kg in a sample volume of 0.283 m3 (10 SCF). 1.3 Units--The values stated in either SI units are to be regarded separately as standard. 1.4 Mention of trade names or organizations in this practice does not constitute endorsement or recommendation. Other manufacturers of equipment or equipment models can be used. 1.5 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.
Keywords
LNG; liquefied natural gas; CNG; compressed natural gas; natural gas; compressor oil; NGV; natural gas vehicle
Rationale
This practice is intended to measure oil carryover from lubricated natural gas compressors used to compress natural gas to CNG or LNG. Uncontrolled oil carryover from lubricated natural gas compressors can adversely affect NGV performance. In some instances, small amounts of oil will accumulate in vehicle pressure regulators and slow their response. It can also affect other components of the engine fueling system. Erratic engine performance, under fueling, or engine shutdown can occur. Such incidents have been reported by operators of NGV fueling stations and vehicles.
The title and scope are in draft form and are under development within this ASTM Committee.
Work Item Status
Date Initiated: 03-15-2015
Technical Contact: Allan Morrison
Item: 002
Ballot: D03.05 (18-01)
Status: Will Reballot Item
Item: 006
Ballot: D03 (19-01)
Status: Will Reballot Item
Item: 001
Ballot: D03.05 (20-02)
Status: Will Reballot Item
Item: 001
Ballot: D03 (21-01)
Status: Will Reballot Item