PROMET EExd Process Moisture Analyzer Sampling Systems
Installation, Operation & Maintenance Manual
and User
Guide
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4
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www.michell.com
1.
OVERVIEW
The PROMET EExd Sampling Systems are designed for continuous on-line measurement
and monitoring of the moisture content of a hydrocarbon gas. The sampling systems can
be located close to the process gas sample take-off point in a potentially explosive
environment designated zone 1 hazardous area.
PROMET Process Moisture Analyzer Sampling Systems are specifically designed for the
measurement of moisture content in Natural Gas. The systems are configured with the
necessary filtration, pressure letdown and flow control required for measurements at
pressure before finally venting to an atmospheric or a low pressure flare line system. A
fast-loop bypass flow arrangement is included to reduce sample flow response time lag
and enabling the filter to be drained automatically of any potential hydrocarbon liquids
and hydrates formed.
Two separate series of sampling systems are available; one designed for the
requirements of Trace Moisture applications such as molecular sieve drying at LPG
plants and one for the more general moisture measurements in Natural Gas from
processing through pipeline transmission. Each of these systems can also be supplied
as either 1 or 2 channel systems. The more general Natural Gas systems are supplied
with triple filtration consisting of particulate and membrane filter and glycol absorption.
For systems intended to measure Trace Moisture levels, single filtration is provided that
consists of a stainless steel mesh particulate filter.
The sampling systems gas handling components are supplied mounted on a chassis
panel that can be fitted within a stainless steel insulated enclosure. The enclosure
provides environmental protection to IP66 and fitted with mounting brackets
suitable
for wall mounting.
Sampling systems fitted within enclosures are temperature controlled to maintain a
constant temperature environment of at least 10 oC above the highest envisaged dew
point temperature independent of surrounding temperature variations. The temperature
control system consists of a heater controlled by a fixed preset thermostat to provide
internal ambient air temperature control of >15 oC. For higher temperature control,
systems can be supplied with a heater controlled by an adjustable setpoint thermostat
to achieve internal ambient air temperature control up to 60 oC for maintaining more
stable measurement conditions for installations in adverse climates.
All sample gas wetted metallic parts in AISI 316L stainless steel with Viton soft parts
that comply with the NACE standard MR-01-75 (latest edition). Tube fittings are twin
ferrule compression type. All gas and cable entries are located in the base of the
enclosure.
