LPG, LNG and other liquid hydrocarbon standard mixtures
NPL can produce LPG (liquefied petroleum gas), LNG (liquefied natural gas) and other liquid hydrocarbon standards in two forms of vessel technology: constant pressure (piston) cylinders or dual-port valve dip-tube cylinders.
The constant pressure cylinders employ a piston as a physical barrier maintained by high pressure, which ensures that the composition of the mixture remains. The cylinders also possess an integral mixer that guarantees users draw homogenous samples of constant composition. Cylinders of 300mL, 500mL or 1L volume are available.
The dual-port valve dip-tube cylinders do not have any physical barrier between the gas and the liquid hydrocarbon mixture, however the dual port valve does allow for a overpressure of gas (usually helium) to be maintained. These cylinders have an internal volume of 10L.
Some example liquid hydrocarbon mixtures are shown in the table below. Other mixtures are available and it may also be possible to include components not listed in the table. Please contact us for further information.
| Component | Amount Fraction (% mol/mol) | ||
| Liquefied Petroleum Gas (C3 rich) | Liquefied Petroleum Gas (C4 rich) | Liquefied Natural Gas | |
| Methane | - | - | 80 |
| Ethane | 0.5 |
- |
10 |
| Propane |
70 |
17.5 |
2.5 |
| Propene | 15 |
4.0 |
- |
| iso-Butane | 2.0 |
10 | 2.0 |
| n-Butane |
5.0 | 60 | 2.0 |
| But-1-ene |
1.5 | 2.5 | - |
| iso-Butene |
1.0 | 2.0 | - |
| trans-2-Butene |
- | 1.75 | - |
| cis-2-Butene |
- | 1.25 | - |
| iso-Pentane |
- | 0.5 | 1.0 |
| n-Pentane |
- | 0.5 | 1.5 |
| n-Hexane |
- | - | 1.0 |
Guide to handling liquid hydrocarbon mixtures in constant pressure cylinders 
Contact
Customer Service tel: +44 20 8943 8637
E-mail: gases_enquiries@npl.co.uk