Enviro Vault offers internal chamber for valves, heaters, and spill containment
By locating the valves inside the Vault, they are kept warm, preventing any issues caused by freezing.
Several years ago, a trucker
looked at a tank in the Alberta
Oilfields and thought, “there
must be a simple way to utilize
the tank itself to solve the problems the
operators face on a daily basis.” The
solution to this problem was the Enviro
Vault. This simple, patented system
has been used in thousands of tanks
ever since and is fast becoming the
standard in oilfield tank design. This
system addresses requirements seen in
all tanks regardless of the material of
construction, contents, or valve configuration.
These requirements may
include:
Keeping valves from freezing.
Transferring heat into the fluid to prevent
the contents from freezing.
Providing a safe system to protect
personnel.
Providing spill containment for
valves.
Ease of installation, including retrofits.
Keep your valves warm
Perhaps the most common cause of
tank related spills could be traced to
the valves that are required to facilitate
the transfer of fluid. These valves are
typically located on the external surface
of the tank and are subject to damage
from contact. They are also located
in the ambient environment, which
in Canada means the very real possibility
they will freeze, perhaps even
split from ice formation or be damaged
if forced open. External boxes have
been used but often create transportation
issues and offer little if any secure
spill containment.
By locating the valves inside the
Vault, they are kept warm, preventing
any issues caused by freezing. The heat
can be provided by one of two methods.
The first is to install a heater
inside the Vault. This is most often
accomplished by the use of a catalytic
heater, fuelled by either propane or
natural gas. As these heaters are
designed for hazardous locations, they
are completely safe for all installations.
The second method is accomplished
if the tank contains warm fluid
already. The Vault is heated by the
fluid surrounding it, thereby providing a warm environment for the valves. By
keeping the valves inside and warm,
the owner saves on the cost of thawing
valves if required, as well as standby
costs for truckers that encounter frozen
valves.
Keep your tank’s contents
from freezing
The same method of heat transference,
namely the Vault being surrounded
by fluid, can be used to transfer heat
into the fluid. This is accomplished by
the use of the afore-mentioned catalytic
heater, or an electric heater rated for
the area classification. This allows the
operator to provide an adequate
amount of heat to prevent the contents
from freezing, while at the same time
providing heat for any appurtenances
that may be installed inside the Vault.
Many times the operator is looking
to just provide freeze proofing for the
contents. The options to accomplish
this are very limited and many of them
are ineffectual. Tube tracing is expensive
and transfers little heat. Internal
coils require much maintenance, are
very expensive, and necessitate entry
into a confined space. The use of a
firetube burner assembly is also
expensive, requires tanks’ modification,
and is a high maintenance item. It
also releases a large amount of
“Greenhouse” gases, something to
consider in these days of the Kyoto
Accord. The use of a Vault is relatively
inexpensive and provides many additional
advantages.
Safety for personnel
Safety is a major concern for all
operators. Confined space entry is one
issue that should be avoided at all
costs. Some manufacturers provide an
insulated “shack” that is affixed to the
side of the tank. This provides an area
to house the valves, etc. The use of this
type of installation requires that the
operator physically enter the building
to perform any functions such as gauging,
maintenance, etc. If there is a possibility
of dangerous gases being present,
they may be required to don safety
equipment such as a self-contained
breathing apparatus. They may also
require a second person to act as a
backup in case of an equipment failure.
The use of a Vault negates the
necessity of entering the area at all.
The large doors facilitate the access to
all internals without having to physically
enter the hazardous area. If
required, a portable gas detector with a
probe can be used to check the air
quality prior to opening the Vault, or a
fixed ambient detector can be installed
inside. Even if there were to be an incident,
the operator would fall away
from the tank into fresh air, rather than
be trapped inside a building. The use
of a Vault also provides the advantage
of keeping all the valves at ground
level, thus eliminating the need to
climb ladders to access valves.
Spill containment
With more focus on environmental concerns these days, spill containment
is a high priority for all operators.
Whether we are talking about a 5000
barrel (800 cubic metre) oil tank, or a
small chemical tank, a spill is a major
concern. The cost of losing the product
is minor compared to the cost of cleaning
up a spill. Reclamation costs can
easily run into the hundreds of thousands
of dollars depending on the volume
and makeup of the fluid lost. No
operator wants to see their name in the
headlines when it is to describe an
environmental disaster.
Many spills originate with the
valves. These provide the interface or
connection with trucks, other lines,
etc. They must be opened and closed
on a constant basis resulting in wear.
Over time, this can result in a leaking
valve. Another possibility is human
error; perhaps the operator did not
close it fully. Connecting and disconnecting
a truck line can result in a
small amount of fluid being spilled on
the ground. While this loss might be
minor, over time you end up with contaminated
soil that must be reclaimed.
The valve could have an ice plug in it
that does not allow it to be fully closed.
Once the ice plug melts, you have a
spill.
Most valves are located on the outer
wall of the tank where they are prone
to being hit and causing a rupture that
could result in the loss of all of the
fluid contained in the tank. Even
something as simple as an operator
tripping on a valve handle could result
in the loss of product and money as
well as putting the safety of that operator
at risk.
The use of an Enviro Vault can prevent
these issues from happening. By
housing the valves in an internal chamber
they are protected from all of the
scenarios mentioned above. Any spills
from a leaking valve or the loss from a
hose connection are contained within
the Vault. If required, a fluid level sensor could be mounted inside the Vault
so that an alarm could be sounded if it
detected liquid at a certain level. A
pipe is situated at the bottom of the
Vault chamber to facilitate solids
cleanout if required. Sample ports can
be located in the Vault as well so that
there is no chance for contamination.
The use of the heat from the fluid surrounding
the Vault, or the heater
mounted inside the Vault ensures that
everything is nice and warm so that no
freezing can occur. Use of the Vault
eliminates the cost and requirement for
field-installed add-ons. Vault equipped
tanks are “field ready” when shipped
from the manufacturer.
Another issue that is becoming
more prevalent as the cause of spills is
vandalism. All Vaults have the ability
to be locked so that access to the
valves is impossible. This will prevent
someone from intentionally opening a
valve to create an environmental disaster.
Installation
The use of an Enviro Vault has been
made very easy, either by installing it
in a new tank, or retrofitting an existing
tank. Many tank manufacturers
have been licensed to install this
patented product. A Vault equipped
tank requires no additional set-up upon
delivery, and requires no special trucking
procedures. It can be designed to
the customer’s specifications regarding
number and placement of valves, location
of heater, etc. It can be installed in
a double walled tank and still maintain
the integrity of the containment system
If the operator is looking at retrofitting
an existing tank, he has two
options. First is a weld-in model that is
similar to the type of Vault that would
come in a new tank. This would, of
course, require that the tank be emptied
of all fluid and be safe for hot
work.
Another popular option that has
been proven to be very cost-effective is
the “bolt-in” model. It is, as its name
implies, bolted into an existing tank in
place of a manway door. The Vault can
be equipped with valves, heater, etc.,
just as in a weld-in unit. It can be coated
to the customer’s specifications and
comes complete with hinged door and
any other options required. The bolt
pattern will be identical to the door it is
replacing whether round, square, or
rectangular. It can be installed in steel,
fibreglass, or plastic tanks without
requiring the cleaning of the tank. It is
only necessary to lower the fluid level
below the door being replaced.
Installation then is only a matter of
removing the door, sliding in the Vault,
and then replacing the bolts. This can
be accomplished with a minimum of
equipment and in a very short period
of time.
Contact: Marty Schlager, VP and
General Manager of Enviro Vault Ltd,
E-mail: mschlager@envirovault.com
See our home page on how to order your subscription. We regret we can
only accept orders from Canada.
