Rego ESV Series Quick Start Manual

RegO Emergency Shutdown Valves (ESVs)
®
LP-Gas Emergency Shut-Off Valves (ESV's)
Why and how they should be used for Bobtail Filling
and Transport Unloading.

General Information

The primary purpose of Emergency Shut-Off Valves in bobtail filling
and transport unloading is to allow quick shut-off of liquid and vapor
flow in the event there is an accidental pull-away of a truck or a hose
rupture, both of which could cause a fire.
A system using Emergency Shut-Off Valves will not prevent some
spillage of liquid and vapor, but the total system should be constructed
so this spillage will be kept to a minimum.
This can be accomplished either by making possible, quick action by
the driver or plant personnel in closing the valves by manual remote or
pneumatic remote actuation; or in case of a pull-away, by automatic
closing of the liquid valve by means of a cable connected to the liquid
hose.
By minimizing the presence of liquid and vapor, the chance of a fire or
explosion will be reduced. In case of a fire, thermal links at the valves
or at other appropriate locations could close the valves and prevent
further release of liquid and vapor.
The valve closing systems will be discussed later in this section. The
user should decide which system is most appropriate, depending on
the piping configuration and the general layout of the filling/-unloading
area.

ESV Application for Bobtail Loading and Transport Unloading

A very important function of the typical LP-Gas storage plant is to
transfer LP-Gas into bobtails for delivery to customers. How efficient-
ly and rapidly these bobtails can be filled often determines the number
of customers that can be served each day, as well as how many bob-
tails are required to satisfactorily serve all customers. Therefore, the
selection of an ESV for the bobtail liquid loading line should be done
with care so as to maximize efficiency in filling and have year-round
dependability.
The RegO® 2" liquid ESV (6016) has a full open port so that the
restrictions of flow would be no more than you would expect through
an equivalent length of 2" schedule 80 pipe. To improve the overall effi-
ciency of the system, the valve was also designed as an operating
valve so it could replace an existing globe or angle valve already
installed at the end of the fixed piping. Thus, installing a RegO® ESV
could actually result in a more efficient pumping operation than the
existing system.
Equally important in the consideration of an ESV is its performance in
an emergency, especially bobtail pull-aways. According to the NPGA,
it is the bobtail filling transfer process that produces almost 99% of all
bulk plant accidents and fires. Therefore, when selecting the proper
ESV for bobtail filling, also consider the dependability of performance,
and simplicity of operation and maintenance.
The RegO® ESV clearly indicates to the operator its open or closed
position. It allows full manual control by the operator and provides
means for remote operation in emergencies from either in front of the
valve or in the rear.
No complicated systems of pulleys and cables are necessary since
direct, straight pulls will close the valve. Means are even provided to
secure a length of cable to the transfer hose so as to produce an
automatic closing in the event the driver pulls away without discon-
necting the hose.

NFPA Provisions (1986)

The pertinent provisions of NFPA Pamphlet 58, as they apply to
Emergency Shut-Off Valves and how they are to be installed, are as fol-
lows:
2
Section 2-4.5.4 Emergency shutoff valves shall be approved and
incorporate all the following means of closing:
(a) Automatic shutoff through thermal (fire) actuation. When fusible
elements are used they shall have a melting point not exceeding 250°
F. (121° C).
(b) Manual shutoff from a remote location.
(c) Manual shutoff at the installed location.
This provision sets for the basic criteria for the emergency shutoff
valve, a key valve in the protection of many liquid transfer operations.
Actuating means for remote control may be electrical, mechanical or
pneumatic.
Many systems use a pneumatic system where the tubing itself acts as
a fusible element releasing the pressure holding the valve open. With
respect to the feature of manual shutoff at the installed location, it is
recommended that this valve be operated occasionally. Also, the sys-
tem should be tested periodically to determine that it will function
properly.
Section 3-2.7.9 on new installations, and by December 31, 1980 on
existing installations, (1) stationary single container systems of over
4,000 gal. (15.1 m3) water capacity, or (2) stationary multiple con-
tainer systems with an aggregate water capacity of more than 4,000
gal. (15.1 m3) utilizing a common or manifolded liquid transfer line,
shall comply with 3-2.7.9 (a) and (b).
(a) When a hose or swivel type piping 1
transfer or a 1¼" or larger vapor hose or swivel type piping is used in
this service (excluding flexible connectors in such liquid and vapor
piping), and emergency shutoff valve complying with 2-4.5.4 shall be
installed in the fixed piping of the transfer system within 20 ft (6m) of
lineal pipe from the nearest end of the hose or swivel type piping to
which the hose or swivel type piping is connected. The preceding
sizes are nominal. Where the flow is only in one direction, a backflow
check valve may be used in lieu of an emergency shutoff valve if
installed in the fixed piping down-stream of the hose or swivel type
piping, provided the backflow check valve has a metal-to-metal seat or
a primary resilient seat with a secondary metal seat not hinged with
combustible material. When either a liquid or vapor line has two or
more hoses or swivel type piping of the sizes designated, either an
emergency shutoff valve or a backflow check valve shall be installed
in each leg of the piping.
(1) Emergency shutoff valves shall be installed so that the tempera-
ture sensitive element in the valve, or a supplemental temperature
sensitive element [250° F. (121° C) maximum] connected to actuate
the valve, is not more than 5 ft. (1.5 m) from the nearest end of the
hose or swivel type piping connected to the line in which the valve is
installed.
(b) The emergency shutoff valve(s) or backflow check valve(s) speci-
fied in 3-2.7.9 (a) shall be installed in the plant piping so that any
break resulting from a pull will occur on the hose or swivel type piping
side of the connection while retaining intact the valves and piping on
the plant side of the connection. This may be accomplished by use of
concrete bulkheads or equivalent anchorage or by the use of a weak-
ness or shear fitting. Such anchorage is not required for tank car
unloading.
These provisions have been interpreted by the National Propane Gas
Association as to how bobtail filling and transport unloading stations
should be configured. The diagrams shown here are in essential con-
formance with NPGA Bulletin 128-77.
" or larger is used for liquid
½