American Oil and Gas Reporter - May 2019 - 66

SpecialReport: Gas Compression & Vapor Recovery
solution to this issue is using sloping
piping of adequate inner diameter from
the tank that is routed to a drip pot (i.e.,
scrubber) to ensure that liquids do not
collect in the line and create blockages.
Also, the scrubber can remove liquids
that can harm VRU compressors and
cause smoking conditions in enclosed
combustors/flares.
Gas Carry-Through
Natural gas carry-through can be caused
by pressure increase during normal separator dump events and also can occur
when separator dump valves are stuck in
open position (i.e., a valve failing to
reseat and leaking gas into a tank). In
this case, storage tank pressure relief devices will open and vent gas on a regular
basis to relieve the increased pressure. If
the repeated venting from pressure relief
devices is not related to unintentional
gas carry-through, the following corrective
actions are recommended:
· Increasing the pressure relief device
pressure set point if there is sufficient
margin between the set point and the rated

pressure of the storage vessel while continuing to safeguard storage vessel integrity;
· Taking steps to decrease the liquid
pressure drop experienced at the storage
vessel; and
· Replacing the tank with a storage
vessel that is rated to a higher pressure
and use higher pressure set points.
Facility design should take into account
production rates and operating pressures
in sizing VRUs. Again, infrared cameras
can be used for onsite inspections for
carry-through of vent gas caused by stuck
dump valves.
By design, pressure relief valves are
safety devices that protect vessels from
over-pressurization and should remain
closed during normal operations. They
are not process vents that should discharge
during normal operations. The EPA alert
states that the valves should have a
pressure setting that is low enough to
protect vessel structural integrity and
avoid overpressurization, but high enough
to exceed storage vessel operating pressures during normal operation.
When a pressure relief valve is found

ARTICLE
REPRINTS

Leverage AOGR's communications with
professional reprints and e-prints designed
with four-color custom presentations!
Order a quality reproduction of an article in an organized
format with the addition of your advertisement and/or
company logo along with other company information.
*Available on high gloss 70-80 pound text paper
or 100 pound gloss cover stock. We can deliver
from 1,000 to 10,000 copies, or more!

The marketing tool that simply makes sense!

w w w. a o g r. c o m
66 THE AMERICAN OIL & GAS REPORTER

NORTH AMERICA: 1-800-847-8301
INTERNATIONAL: 001-316-788-6271

to be venting to the atmosphere, actions
should be taken to verify proper valve
reseating after opening. For valves that
are opening on a frequent basis, the operator should determine the cause. Actions
to take can include increasing the pressure
set point for the pressure relief valve
(this requires an adequate safety margin
between the set point and the storage
vessel's rated pressure), decreasing the
operating pressures experienced at the
storage vessel, and using a higher pressure-rated storage tank and a higher set
point for the pressure relief valve.
Of course, the operator always must
consider safety issues with any pressure
relieving devices, including adjusting their
operational settings. This is another area
where infrared cameras can be used to inspect pressure relieving devices and thief
hatches, and to measure and sample leaks.
Thief hatches and pressure relief devices
should be inspected regularly to ensure
good seals. Installing quality gaskets on
thief hatches and regularly inspecting gaskets
will ensure proper sealing. It is also important
to implement procedures to ensure thief

M
id
Ac Con

Pa tiv tin
ge it
en
72 y
t

MAY 2019
The "Better Business" Publication Serving the Exploration / Drilling / Production Industry

Gas Compression
& Vapor Recovery
Page 54
Chad Warmington
President
OIPA-OKOGA
"The Oklahoma
merger represents the
new mix of the two
organizations and
what that means."
Page 85
Steve Layton
Chairman CIPA
"The powerful voices
of our diverse and
united workforce are
being heard in the
Capitol and in our
local communities."
Page 95

Mark Hughes
Chairman KOGA
"Forming broadbased coalitions only
strengthens our
resolve to pass sound
public policy for the
good of Kentucky."
Page 99

For more information and
to order reprints, contact:

Nora Mota Magill
nmotamagill@aogr.com
http://www.aogr.com
American Oil and Gas Reporter - May 2019

Table of Contents for the Digital Edition of American Oil and Gas Reporter - May 2019
