IP 317: Determination of residues in liquefied petroleum gases - Low temperature evaporation method

Overview:

This standard specifies a method for the determination of
the  materials   weathering   above  38 °C  which  may  be present  in  liquefied  petroleum gases  
(LPG).

NOTE 1    The  results  obtained  when  testing  liquefied  petroleum  gases that  contain  
alcohols  to   enhance  their  anti-icing  behaviour   may  be affected by the alcohols.

NOTE  2    The result  may be expressed  in  terms of measured  volumes  or indices derived  from
these volumes.  In either  case, the  method provides an indication of  the quantity  and nature of
materials in  the product that are   substantially    less    volatile    than    the    liquefied
petroleum    gas hydrocarbons.

NOTE 3    Control over the residue content is of considerable importance in  end-use  applications.
In  liquid  feed  systems  residues  may  lead  to troublesome  deposits  and,  in  vapour  
offtake  systems,  residues  that  are carried  over  may  foul  regulating  equipment.  Those  
that  remain  will accumulate,   may   be   corrosive,   and   will   contaminate   any   following
product.  Water,  particularly  if  alkaline,  can  cause  failure  of  regulating equipment  and
corrosion  of metals.