Marshall Excelsior Excelerator ME993-16 Owner's manual

ME993-16 AND ME993-24
FLANGED INTERNAL VALVE
INSTALLATION AND OPERATION
Marshall Excelsior Company Marshall Excelsior Europe LTD
1506 George Brown Drive Marshall, MI 49068 90 Brynteg Road
Phone [phone] Fax [phone] Gorseinon, Swansea, SA4 4FR - UK
www.marshallexcelsior.com 01382-714308
The contents of this publication are for informational purposes only. While every effort has been made to ensure accuracy, these contents are not
to be construed as warranties or guarantees, expressed or implied, regarding the products or services described herein or for their use or
applicability. Marshall Excelsior Co. reserves the right to modify or improve the designs or specifications of such products at any time without
notice. The MEC™ logo is the trademark of Marshall Excelsior Co.
Form #999 IOM ME993-16 & ME993-24 Rev C 5/8/19
!WARNING!
Failure to follow these instructions or to properly install and
maintain this equipment could result in an explosion and/or
fire causing property damage and personal injury or death.
MEC equipment must be installed, operated, and maintained
in accordance with federal, state, and local codes and
manufacturer's instructions. The installation in most states
must also comply with NFPA No. 58, and ANSI/CGA G-2.1.
For installation in the European Union, the equipment must
also comply with PED/TPED and EN ISO standards. Periodic
inspections, intermediate inspections and exceptional checks
of transportable pressure equipment should be carried out
in accordance with the Annexes of Directive 2008/68/EC and
with 2010/35/EU Directive (TPED) to ensure continued
compliance with their safety requirements.
Only personnel trained in the proper procedures, codes,
standards, and regulations of the LP-Gas industry should
install and service this equipment.
The internal valve must be closed except during product
transfer. A line break downstream of a pump may not
actuate the excess flow valve. If any break occurs in the
system or if the excess flow valve closes, the system should
be shut down immediately.
WARNING: These products contain a chemical known
to the state of California to cause cancer and birth
defects or reproductive harm
Scope of the Manual
This manual covers instructions for the ME993-16 and
ME993-24 “Excelerator” Series 2” and 3" triple flange
internal valves.
Introduction
ME993-16 and ME993-24 “Excelerator” Series Internal
Valves are designed to provide accelerated equalization of
tank pressure and downstream line pressure, providing
fast valve response time for quick opening. These internal
valves are frequently used on bobtail and transport truck
tanks for liquid gas delivery, but they may also be used on
large stationary storage tanks and on in-line installations in
liquid or vapor gas transfer applications. U.L. listed types
are designed for use with Propane or NH3(Anhydrous
Ammonia) services. Non U.L. listed models are available
with a variety of trim types and body styles and can be
used on other compressed gases, but the installer should
check with the factory to make sure the valves are suitable
for the particular service. Actuation of the valve can be
achieved manually, by cable, or with a pneumatic actuator.
Features
Excelerator equalization bleed area - Provides high
bleed flow for quick opening.
Unique Serviceability Features - Accessible
stainless steel stem hex and socket drive retaining
screws for easy maintenance.
Durable Design:
oStainless poppet and stem with hardened, low
friction coating operates smoothly for a long
wear life
oFully captured main seal and molded-on bleed
seal will not "Blow-out"
oLarge poppet retaining thread will not break
during reverse flow fill
oIntegral travel stop
oStainless steel roller cam
Excess Flow Closure - Functions when flow exceeds
the rated capacity of the valve or piping is sheared
off at the valve.
Back Check Feature - Allows reverse flow filling
with or without actuator device in valve open
position.
Spring loaded Polytetrafluoroethylene (PTFE) stub
shaft packing with auxiliary wiper seals
Rulon® bushings at critical wear points.
Manual, Cable, or Air Open/Close valve actuators.
Thermal Fusible links or plugs melt at 212°F
(100°C) and allow valve closure in the event of a
fire at the valve.

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
Description
ME993-16 and ME993-24: The ME993-16 and ME993-24
triple flanged internal valves are intended for transport
truck applications where the pump must be lowered to
clear the truck frame or other obstacles. A shear section in
the lower body permits the valve to shear off in the event
of an accident, leaving the shutoff within the tank.
Both internal valves can be used with transports and on
stationary storage tanks. The valves can be operated by
cable or with air.
Designed for use with Propane or Anhydrous
Ammonia at ambient temperatures, the valves can be
used on other compressed gases, but the user should
check with the factory to make sure the valves are suitable
for the particular service and application.
SPECIFICATIONS
Body Size and End Connection Styles:
ME993-16 Inlet:
2-inch CL300 RF Flange
(2 7/16-inch / 62 mm diameter bore)
Outlet: 2” CL300 RF Flange
ME993-24 Inlet:
3-inch CL300 RF Flange
(3 5/8-inch / 92 mm diameter bore)
Outlet: 3” CL300 RF Flange
Maximum Allowable Inlet Pressure:
500 psig / 27.6 bar WOG
Excess Flow Springs:
3” (vertical down): 175, 250, 300, 375, 400, 475 & 500 gpm
(662, 946, 1136, 1420, 1514, 1798, 1893 lpm)
2” (vertical down): 110, 160 & 260 gpm
(416, 606, 984 lpm)
Temperature Capabilities:
-20° to 150°F / -29° to 66°C
Approximate weight:
ME993-16: 35 pounds / 16 kg
ME993-24: 60 pounds / 27 kg
DOT Internal Self-Closing Stop Valve Requirement:
U.S. Department of Transportation (DOT) regulations
49CFR§178.337-8(a)(4) require each liquid or vapor
discharge outlet on cargo tanks (except for cargo tanks
used to transport chlorine, carbon dioxide, refrigerated
liquid, and certain cargo tanks certified prior to January 1,
1995) to be fitted with an internal self-closing stop valve.
MEC ME993 Series internal valves comply with the internal
self-closing stop valve requirement under the DOT
regulations.
Installation
Internal Valve
Coat both sides of the spiral wound gasket with Dow
Corning #111 silicone grease or equivalent. An ASME
CL300 RF flange with a modified bore (see Figure 1) must
be installed in the tank. Special stud bolts, furnished with
the valve, are assembled into this flange. The internal
valve and the pump or piping flange can then be installed
as shown in Figure 2.
On valves so equipped, the filter screen should be
removed if the valve is to be used for both filling and
withdrawal service or for filling alone. Filling with the filter
screen installed is not recommended.
A hydrostatic relief valve does not need to be installed
adjacent to the valve since the internal valve automatically
relieves excessive line pressure into the tank

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
Keep piping from the valve outlet to the pump full size and
as short as possible with a minimum number of bends.
Reduction in pipe size to suit smaller pump inlets should
be made as close to the pump as possible using forged
reducers (swage nipples) or venturi tapers rather than
bushings. This assures minimum flow resistance and
efficient pump operation.
If the valve is also used to provide excess flow protection,
the flow rating of the piping, fittings, pump, valves, and
hose on both the inlet and outlet of the internal valve
must be greater than the flow rating of the integral excess
flow valve within the internal valve. If branching or other
necessary restrictions are incorporated in the system
which reduces the flow rating to less than that of the
excess flow valve rating, the internal valve will not give
excess flow protection.
After installation check all joints for leaks using a suitable
leak detector solution such as Marshall Excelsior low-temp
leak detector before putting the valve into service.
Selectively Filling Manifolded Tanks
MEC internal valves provide positive shutoff in only one
direction, from out of the tank to downstream of the
valve. The internal valves are designed to allow gas to
flow into a tank when the downstream line pressure
exceeds tank pressure. If you want to selectively fill one
or more of the other tanks in a tank manifold system,
you must place a positive shutoff valve downstream of
the internal valve, otherwise, all tanks will be filled at
the same time and at about the same rate.
Actuators
The remote operating control system for the internal valve
is extremely important, and it must be installed to
conform with the applicable codes. DOT MC331, for
example, most generally applies for trucks. MEC offers
both cable controls and pneumatic actuator systems to
operate the internal valves. It may also be possible to use
cable controls from other manufacturers or to fabricate a
linkage mechanism.
Any control system requires thermal protection (fuse links)
at the valve, at the remote control point and, if necessary,
near the hose connections. The instruction manuals for
MEC actuator systems show how to install the fuse links.
Installation instructions on MEC MEP650 (Cable Control
Mechanism) are in Form #935, ME980-905-25 and ME980-
905-50 (Remote Release) are in Form #941. Pneumatic
actuator installation is covered in Form #401 and Rotary
actuator installation is covered in Form #462. ME990-24
latch/remote release instructions are in Form #934.

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
The operating linkage must allow the operating lever to
move from the fully closed position to within 2° of the fully
open position. The linkage should not apply strong force to
the lever past the fully open position or the valve could be
damaged.
NOTE
The use of non-MEC actuators may result in leakage of
the gland packing caused by premature wear. In addition
to premature wear, the use of non-MEC actuators may
result in lower than expected flow rates and possible
leakage across the valve seats.
!CAUTION!
The internal valve's closing spring is not designed to
overcome drag in the control linkage in order to close the
valve. Depending upon the control system used, an
external spring or positive closing linkage may be
needed. Be sure the control system is installed to prevent
binding that could cause the valve to stick in the open
position.
Excess Flow Operation
The internal valve contains an excess flow function, or
"integral excess flow valve," that is designed to close when
the flow exceeds the flow rating established by MEC.
MEC's integral excess flow valves installed on a bobtail
truck or transport can provide protection against the
discharge of hazardous materials during an unloading
operation of a bobtail truck or transport in the event that
the pump or piping attached directly to the internal valve
is sheared off before the first valve, pump, or fitting
downstream of the internal valve, provided that the cargo
tank pressure produces a flow rate greater than the valve's
excess flow rating.
Likewise, if the internal valve is installed on a stationary
tank or in the related downstream piping system, the
integral excess flow valve can provide protection against
an unintentional release of hazardous materials in the
event that a pump or piping attached directly to the
internal valve is sheared off before the first valve, pump,
or fitting downstream of the internal valve, provided that
the flow of product through the internal valve reaches the
rated flow specified by MEC.
!EXPLOSION HAZARD!
Restrictions incorporated in the discharge system of a
bobtail truck or transport or of a stationary tank (due to
pumps, pipe and hose length and dimensions, branching,
elbows, reductions in pipe diameter, or a number of
other inline valves or fittings), low operating pressure as
a result of ambient temperature, or a partially closed
valve downstream from the integral excess flow valve,
can restrict the rate of flow through the internal valve
below the level necessary to actuate the integral excess
flow valve. Therefore, DO NOT USE the excess flow
function of the internal valve for the purpose of providing
protection against the discharge of hazardous materials
in the event of a rupture of hose or piping at a point in
the discharge system downstream from the first valve,
pump, or fitting downstream of the internal valve.
The internal valve is designed with an internal bleed
feature for equalization of pressure. After the integral
excess flow valve closes, the leakage through the bleed
must be controlled or a hazard can be created. For this
reason the operator must be familiar with the closure
controls for the internal valves and must close the
internal valve immediately after the integral excess flow
valve closes.
Failure to follow this warning could result in serious or
fatal personal injury or property damage from a fire or
explosion.
DOT Passive Shutdown Equipment Requirement -
DOT regulations 49 CFR§173.315(n)(2) require certain
cargo tanks transporting propane, anhydrous ammonia
and other liquefied compressed gases to be equipped with
passive emergency discharge control equipment that will
automatically shut off the flow of product without human
intervention within 20 seconds of an unintentional release
caused by complete separation of a delivery hose. The
design for each passive shutdown system must be certified
by a Design Certifying Engineer (DCE) and all components
of the discharge system that are integral to the design
must be included in the DCE certification. The DCE
certification must consider any specifications of the
original component manufacturer. In the case of
downstream ruptures in hose or piping, a variety of
operating conditions routinely encountered during an
unloading operation restrict the rate of flow through the
integral excess flow valve and make such a valve
unsuitable to serve as the means of passive shutdown
required under 49 CFR§173.315(n)(2). Such variables
include restrictions incorporated in the discharge system
(due to pumps, pipe and hose length and dimensions,
branching, elbows, reductions in pipe diameter, or a
number of other in-line valves or fittings), low operating
pressure as a result of ambient temperature, or a partially
closed valve downstream from the excess flow valve. Due
to the variety of conditions, in the case of a hose
separation, that can restrict the rate of flow below the
level necessary to activate the excess flow valves, the
integral excess flow function of MEC ME993 internal valves
cannot be used to satisfy the passive shutdown equipment
requirement under/in 49 CFR§173.315(n)(2). Also, a
Design Certifying Engineer cannot include the integral
excess flow valve of a MEC ME993 internal valve as a
component of the discharge system in any DCE
certification under 49 CFR§173.315(n)(2).
!EXPLOSION HAZARD!
DO NOT USE the excess flow function incorporated into
MEC ME990 internal valves to satisfy the passive
shutdown equipment requirement in 49
CFR§173.315(n)(2). DO NOT include the excess flow
function incorporated into MEC ME990 internal valves in
a DCE certification under 49 CFR§173.315(n)(2). The cargo
tank manufacturer must install some other equipment
that satisfies the requirement for passive shutdown
capability under 49 CFR§173.315(n)(2).

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
Failure to follow this warning could result in serious or
fatal personal injury or property damage from a fire or
explosion in the event of an unintentional release of
product during an unloading operation.
Operation
Since the ME993-16 and ME993-24 Series Internal Valves
are most often used on bobtail trucks, the following
procedure applies to that type of application. Follow
these steps:
1. ME993 series internal valves on bobtails and
transports should never be open when the truck is in
motion. If the control system is not interlocked to
prevent this, the operator is responsible to ensure
that the valves are closed.
2. Always open the internal valve before opening any
other valves in the line or starting the pump.
3. Move the lever to the half-open (rapid equalizing)
position (Figure 3, View 2) to equalize pressure. When
the main poppet clicks open, move the operating
lever fully open.
4. Open other line valves slowly to avoid sudden surges
which could slug the excess flow valve shut.
5. If the excess flow valve does close, stop the pump and
close the nearest downstream valve. Move the
internal valve's operating lever back to the rapid
equalizing position (outlined in step 3) and wait for
the valve to click open. Then move the operating
lever fully open and slowly open the downstream
valve.
6. All valves should be completely open when pumping.
(Throttling type valves could prevent the excess flow
valve from closing when required.
7. The operator must always be aware of where the
remote closure controls are located and know how to
operate the controls if an emergency requires valve
closure. When pumping is finished, make a habit of
closing the internal valve from the remote closure
point, thus checking to see that the control actually is
capable of closing the valve and operating correctly.
8. The valve should be open when backfilling through
the valve to fill the tank.
Troubleshooting
Internal Valve Will Not Open: This could be due to leakage
downstream, engaging the pump too soon or from
excessive wear in the internal valve. If excessive volume is
in the downstream system, a longer time is required to
equalize the pressures (tank and downstream) before the
pump can be engaged. To determine if the valve pilot seat
is opening, install a gauge downstream of the valve,
operate the valve actuator; if pressure does not build up to
the tank pressure, the valve pilot seat is not open. This test
should be done with the pump off. If the pilot is not
opening, it may be plugged with dirt or some internal part
may be broken. If by operating the lever manually it can be
rotated past the fully open position, there is something
wrong internally and the valve must be disassembled.
Premature Valve Closure: This can be caused from
engaging the pump too soon, by an underrated excess
flow valve spring, or by an improperly connected internal
valve operating lever which does not fully open the valve.
The trouble could also be from a valve that has its inlet
port obstructed or from sudden line surges. In order to
check the valve opening travel, operate the lever manually
to the full travel, wait until valve opens (usually about 15
seconds), then engage the pump. If the excess flow closes,
the points mentioned above should be investigated.
Internal Valve Will Not Close: The stub shaft could be
binding or the stem could be bent in the valve. Before
disassembling the valve, check the actuator mechanism to
see that it operates freely by disconnecting it from the
valve lever and cycling it several times. Also, operate the
valve lever manually. If it sticks in the open position, the
packing and bushings should be replaced. This should free
the operating mechanism if the valve has not been
damaged internally. Refer to the "Maintenance" section.
Low Flow Capacity: This could be caused by an undersized
internal valve, undersized or long downstream piping,
plugged screens, some other restriction in the
downstream system, or by the bypass valve sticking in the

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
open position. The bypass valve could also be set too low
and be opening prematurely.
Principle of Operation (Figure 3)
The operational schematic depicts threaded valves,
however flanged styles operate in the same manner.
Refer to the schematic drawing, Figure 3. In Figure 3, View
1, the valve is held closed by both tank pressure and the
valve's closing spring. There is no leakage past the resilient
seats in the poppet to the valve outlet in this position.
The valve is opened by moving the operating lever to
approximately midpoint in its 70° travel (Figure 3, View 2).
This allows the cam to place the rapid equalization portion
of the valve stem in the pilot opening, permitting a larger
amount of product to bleed downstream than if the
operating lever was moved to the full open position.
When tank and downstream pressures have equalized in
the bleed position, (after a few seconds), the excess flow
spring pushes open the main poppet (Figure 3, View 3) and
the operating lever can be moved to the full open position.
If tank pressure is greater than the valve's outlet pressure,
the main poppet will remain in the closed position. If valve
outlet piping is closed off by other valves, however,
product bleeding through the pilot will increase until it
nearly equals tank pressure and the main poppet opens.
NOTE
The main poppet will not open if valve outlet piping is
not closed off so that the outlet pressure can approach
tank pressure.
Once the main poppet opens, a flow greater than the
valve's excess flow spring rating or a sufficient surge in
flow forces the main poppet closed against the excess flow
spring (View 4). The pilot valve allows a small amount of
product to bleed, but much less than View 2 where the
rapid equalization portion of the stem is placed in the pilot
opening. When the operating lever is moved to the closed
position, the valve closes completely and seals tightly
(View 1).
Maintenance
!CAUTION!
Do not use these internal valves if they leak, fail to work
properly or have been damaged or have missing parts.
Prompt repairs should be made by a properly trained
serviceman. Continued use without repair can create a
hazardous situation which could result in serious or fatal
personal injury or property damage.
A simple preventative maintenance program for the valve
and its controls will eliminate many potential problems.
MEC recommends these steps be conducted once a
month. Also refer to the Department of Transportation
(DOT) CFR 49 Sections 180.416 and 180 Appendix A and B
which specify monthly maintenance and inspection tests
for cargo tank service internal valves and their actuation
controls.
1. Inspect the operating lever to see that it operates
freely and that there is no leakage around the
retainer nut. If there is sticking or leakage, replace the
packing and bushings. Refer to parts list.
2. Check for tight closure of the seat discs. Any detected
leakage, which is normally caused by disc wear or
dirt, scale or debris embedded in the disc, requires
that the internal valve be removed from service and
repaired. Repair most often requires the replacement
of valve discs. To check for leakage:
a. Close the internal valve and exhaust
downstream pressure. Close the first valve
downstream from the internal valve and note
any pressure build-up using a pressure gauge,
between the closed valve and the internal valve.
If piping is cold allow it to warm to ambient
temperature.
b. Refer to CFR 49 Section 180 Appendix B for
Meter Creep Test Methods.
3. All operating controls should be inspected, cleaned
and oiled. The controls should be checked to see that
they fully open but not over travel the internal valve
operating lever and operate freely to close the valve.
4. Standard construction internal valves must be
removed if the container is to be steam cleaned. Heat
can damage the valve's seats and seals.
5. Standard construction internal valves are not
designed for water service. Immediately after a
container is hydrostatically tested, remove all water
and allow the container to thoroughly dry out.
Parts Ordering
………………………………………………!IMPORTANT...........................
Use only genuine MEC replacement parts. Components
that are not supplied by MEC should not, under any
circumstances, be used in any MEC valve, because they
might adversely affect the performance of the valve, and
could give rise to personal injury and property damage.
When corresponding about this equipment, always
reference the equipment model or series number found
on the nameplate.
Valve
ME993-16
ME993--24
Available Service Kit
ME990-16-SRK
ME990-24-SRK
ME990-16-VRK
ME990-24-VRK
ME990-PGA
ME990-PRK
SRK –Seal Repair Kit
VRK –Valve Repair Kit
PGA –Packing Gland Assembly
PRK –Packing Repair Kit
See parts list for corresponding parts and service kit
components.

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
- Included in service kit
Parts List For ME993-16
ME990-
Ref.#
Description
Qty.
16-SRK
16-VRK
PGA
PRK
1
Body, Carbon Steel
1
2
Stem
1

3
Valve Poppet
1

4
Ex. Flow Spring, Yellow, 110 GPM
1
Ex. Flow Spring, Green, 160 GPM
Ex. Flow Spring, Blue, 260 GPM
5
Spring Seat
1

6
Closing Spring
1

7
Main Valve Seal
1


8
Seal Retainer
1

9
Valve Poppet Screw
4

10
Bleed Disc, Nitrile
1


11
Lock Nut
1

12
Cotter Pin
1

13
Gland O-Ring, Nitrile
1




14
Upper Washer
1

15
Lower Washer
1

16
Guide Bushing
1


17
Guide, Plated Steel
1

18
Stem O-Ring, Nitrile
1


19
1/4" NPT Plug
1
20
Name Plate Screw
2
21
Name Plate
1
22
Gland Assembly, Nitrile
1


22A
Stub
1
22B
Bonnet
1
22C
Wiper, Nitrile
1


22D
Gland Bushing
2


22E
Nylon Washer
1


22F
Female Adapter
1


22G
V-Pack
3


22H
Male Adapter
1


22J
Thick Washer
1
22K
Gland Spring
1
22L
Thin Washer
1
22M
Gland
1
22N
Spring Pin
1


22P
O-Ring, Nitrile
1


22Q
Cam
1
22R
Rivet
1
22S
Roller Bushing
1
22T
Roller
1
23
Flange Gasket
3
24
Cotter Pin / Valve Link
1

25
Lever
1
26
Fusible Link
1
27
1 1/4" Steel (Key) Ring
1
28
Bushing
24
29
Flange Stud
24
30
Nut
24

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19
- Included in service kit
Parts List For ME993-24
ME990-
Ref.#
Description
Qty.
24-SRK
24-VRK
PGA
PRK
1
Body, Carbon Steel
1
2
Stem
1

3
Valve Poppet
1

4
Spring Seat
1

5
Closing Spring
1

6
Main Valve Seal
1


7
Lock Washer
6

8
Seal Retainer
1

9
Valve Poppet Screw
6

10
Bleed Disc, Nitrile
1


11
Lock Nut
1

12
Cotter Pin
1

13
Gland O-Ring, Nitrile
1




14
Upper Washer
1

15
Lower Washer
1

16
Guide Bushing
1


17
Guide
1

18
Excess Flow Spring, Purple, 175 GPM
1
Excess Flow Spring, Black, 250 GPM
Excess Flow Spring, Black, 300 GPM
Excess Flow Spring, Yellow, 375 GPM
Excess Flow Spring, Red, 400 GPM
Excess Flow Spring, Silver, 475 GPM
Excess Flow Spring, Gold, 500 GPM
19
Lever
1
20
Nameplate
1
21
Fusible Link
1
22
Gland Assembly, Nitrile
1


22A
Stub
1
22B
Bonnet
1
22C
Wiper, Nitrile
1


22D
Gland Bushing
2


22E
Nylon Washer
1


22F
Female Adapter
1


22G
V-Pack
3


22H
Male Adapter
1


22J
Thick Washer
1
22K
Gland Spring
1
22L
Thin Washer
1
22M
Gland
1
22N
Spring Pin
1


22P
O-Ring, Nitrile
1


22Q
Cam
1
22R
Rivet
1
22S
Roller Bushing
1
22T
Roller
1
23
Cotter Pin / Valve Link
1

24
1/4" NPT Plug
1
25
Nameplate Screw
2
26
Stem O-Ring
1


27
1 1/4" Steel (Key) Ring
1
28
Flange Gasket
3
29
Bushing
24
30
Flange Stud
24
31
Nut
24

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19

ME993-16 and ME993-24
Form #999 IOM 993-16 & ME993-24 Rev C 5/8/19