Panametrics Sentinel LCT, User Manual

Page: 13 / 248

Sentinel LNG User’s Manual 1
Chapter 1. Features and Capabilities
Chapter 1. Features and Capabilities
1.1 Overview
The Panametrics Sensing
Sentinel LNG
is an ultrasonic liquid flow transmitter that includes a multipath ultrasonic
flowmeter. The entire system is shipped fully assembled and preconfigured.
1.1.1 Applications
The
Sentinel LNG
is designed specifically for the custody transfer of liquified natural gas.
Liquified natural gas, or LNG, is natural gas (predominantly methane, CH
4
) that has been converted temporarily to
liquid form for ease of storage or transport.
Liquified natural gas takes up about 1/600th the volume of natural gas in the gaseous state. It is odorless, colorless,
non-toxic and non-corrosive. Hazards include flammability, freezing and asphyxia.
The liquefication process involves removal of certain components, such as dust, acid gases, helium, water, and
heavy hydrocarbons, which could cause difficulty downstream. The natural gas is then condensed into a liquid at
close to atmospheric pressure (Maximum Transport Pressure set around 25 kPa/3.6 psi) by cooling it to
approximately –162°C (–260°F).
1.1.2 Advantages
The
Sentinel LNG
features numerous unique advantages:
• 0.25% Accuracy
• Capable of handling cryogenic LNG temperatures, typically at –162°C (–260°F).
• Fast response electronics
• Advanced signal processing
• Fully welded on transducers’ buffer rods, resulting in a fully-sealed system.
• Zero pressure drop
• Bi-directional flow capability
• Excellent low-end and high-end resolution
• Active Tw compensation, a compensation algorithm for temperature gradients within the ultrasonic
transducer and buffer system.
• High turndown ratio
• Low sensitivity to many upstream flow disturbances
• Minimal maintenance
• Transducer replacement without the need for pipe shutdown or recalibration
• Removable/replaceable transducers
1.1.3 Meter Components
Figure 4 on page 13 shows the complete
Sentinel LNG
system and each of the items is described in Table 1 and Table 2
below.
No. Component Description Qty
1 Meter Body Measurement section of a Sentinel LNG System. 1
2 Name and Specification
Plate
All pertinent information in a single location. 1
3 Transducer Holder Assembly
Device to support a transducer and provide a mounting point for
the Insertion Mechanism. 4
4 Transducer Flow sensor to transmit and receive ultrasonic waves. 4