Emerson ROC809 User Manual

Bulletin 75.2
D103095X012

March 2021

Type Dosaodor-D

Type Dosaodor-D Odorant Injection System

Figure 1. Type ROC809 Remote Telemetry Unit

Figure 2. Standard Wick Insert Figure 3. Type Dosaodor-D Pneumatic Panel

Introduction

Type Dosaodor-D is a computerized odorant injection
system for natural gas using patented solenoid
injector technology that eliminates the need for
plunger pumps.

Automatic calibration during operation adjusts for any
changes in mechanical components and also detects
failures for alarming. Report by exception alarming is a

congurable option.

The solenoid injectors provide odorant injection

accuracy to be maintained over the entire ow range
of the system, approaching innite turn down.

The system can also be configured to use
redundant injectors and/or an emergency backup or
bypass absorption system.

Type Dosaodor-D

Specications

The Specications section on this page provides the ratings and other specications for Type Dosaodor-D.

Pneumatic Panel:

Material

Stainless steel plate

Installation

Wall mount

Weight

55 to 100 lbs / 25 to 45 kg
(based on configuration)

Overpressure Relief Valve

Stainless Steel with Following Rating Options:

200 psi / 13.8 bar
550 psi / 37.9 bar
870 psi / 60.0 bar

Electrical Protection

Explosion proof

Class I, Division 1 and 2 - Groups B, C, D
Class I, Zone 1 and 2 - Groups IIB+H2, IIA

Mechanical Connections

Odorant Inlet and Discharge

1/4 in. / 6.4 mm OD Tube fitting (double ferrule)

Gas Inlet and Discharge

3/8 in. / 10 mm OD Tube fitting (single ferrule)

Maximum Working Pressure

Supply: 1450 psi / 100 bar
Injection: 870 psi / 60.0 bar

Odorant Flow Rate

0.13 to 3.70 gal/hr / 0.5 to 14.0 l/hr
(0.89 to 24.97 lbs/hr at 6.75 lbs/gal)

Temperature Range

14 to 140°F / -10 to 60°C

Solenoid Valves:

Body Material

304 Stainless steel

Gasket Material

Fluorocarbon (FKM)

Valve Operation

Electromagnetic

Maximum Working Pressure

870 psi / 60.0 bar

Power Requirements

12 Vdc

Electrical Protection

Explosion proof
Class I, Division 1 - Groups A, B, C, D

Stabilizer Filter Type SA/2:

Body Material

Steel

Maximum Working Pressure

1450 psi / 100 bar

Gasket Material

Nitrile (NBR) rubber

Type ROC809 Remote Telemetry Unit:

Refer to Type ROC809 technical specifications.
please go to:

http://www.emersonprocess.com/remote/

Odorant Calibration Cylinder:

Body Material

304 Stainless steel

Maximum Working Pressure

870 psi / 60.0 bar

Maximum Emergency Design Pressure

1450 psi / 100 bar

2

Real time and historical data can be read locally or
remotely by a laptop computer using ROCLINK 800

conguration software, or remotely using third party

SCADA products utilizing ROC or modbus protocol.

ROCLINK 800 software is available for complete
conguration and operation of the system including:

• Display of real time and historical data

• Configuration of alarms

• Archival of historical data

Benets

• Uniform distribution of odorant due to frequent
smaller injections and enhanced absorption from

the wick insertion.

• High turndown ratio. For example, one specific
configuration would evenly distribute odorant at
flow rates from 2000 to 1,000,000 SCFH / 53.6 to

26,800 Nm3/h without mechanical adjustment.

• Automatic calibration of injection system during
normal operation ensuring consistent odorization.

• Environmentally friendly with no venting of gas or

odorant while operating.

• Extremely low maintenance cost.

• Variety of redundancy and backup options for
reliable odorization.

• User friendly configuration software.

• Standard and scalable hardware platform that

supports additional station I/O for AGA flow

calculations and PID control algorithms.

Operation

The Type Dosaodor-D odorant injection system operates
on the basic principle of a fixed differential pressure and
orifice used to measure a non-compressible fluid.

Fixed differential pressure is maintained using double
cut regulation by fixed differential pressure regulators

(Type SA/2 regulators) which reference P2 and reduce

the inlet pressure of a regulating station to
P2 + ΔP. ΔP = 8.7 to 21.7 psi / 0.60 to 1.5 bar,

ΔPmax = 21.7 psi / 1.5 bar (an alternate high

pressure source can be used). This pressure loading

of the odorant calibration cylinder filled with odorant
is used to inject liquid odorant into the downstream

pipeline through an on/off valve (the fixed orifice

with a known flow coefficient that is controlled by the

automated system. The objective of the automated
control system is to maintain an injection rate specified

(1)

)

Type Dosaodor-D

Figure 4. Type Dosaodor-D Intrinsically Safe Panel

by the user which is proportional to the gas flow.

Accuracy of injection is accomplished utilizing relatively

small injections which are automatically resized over a
wide range dependent upon variations in the gas flow.
This results in a turn down ratio for the system that can

exceed 500:1 (the addition of a simple by-pass system

utilizing the odorant storage tank can allow the turn down

ratio to approach infinity). An odorant calibration cylinder

with a fixed volume is utilized to recalibrate the injection
valve flow coefficient each time the odorant calibration

cylinder is refilled.

During the refill cycle the pressure used for injection is

relieved into the downstream pipeline which eliminates

venting of gas to atmosphere or an expansion tank.
Liquid odorant refill of the odorant calibration cylinder is
typically accomplished by using all or some part of the

+ ΔP pressure to load the odorant storage tank thus

P

2

pushing the liquid out of the tank and into the odorant

calibration cylinder, ΔP = 8.7 to 21.7 psi / 0.60 to 1.5 bar.

Since the unit uses only pressure for injection there

are few moving parts in the system resulting in very
little maintenance. Relatively low cost options for both

automated and emergency redundancy for odorization
are also available.

1. Although the valve orice is xed for a specic application the valve can be adjusted manually to accommodate ow rates as small as 2 MSCFH to over 33,000 MSCFH with one injector.

3

Type Dosaodor-D

HAZARDOUS AREA

REGULATING STATION

P1 P2

SAFE AREA

SIGNALS FROM
FLOW COMPUTER

LIQUID
INJECTION POINT

TYPE ROC809

PNEUMATIC PANEL

ODORANT
TANK

Figure 5. General Installation Schematic

The gas flow rate is obtained through either a corrected
gas volume pulse input or an instantaneous flow rate

analog input (4 to 20mA) signal. The gas flow rate can
also be configured manually to a fixed value. Odorant

injection rate is then calculated using accumulated flow

in order to reduce variability.

In cases where the station does not have a flow

computer, the Type ROC809 can be connected directly
to a pulse output from the turbine or an analog output
from a differential pressure transmitter (Rosemount
Types 3051, 3095, etc.).

4