FlowLine LD31-S301 Series User manual

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 1 of 13
Rev C MN301031
DeltaSpan
Intrinsically Safe
Submersible & Waste Water Pressure
Transmitter Manual
LD31-S301, LD31-S311, LD31-S321, LD31-S331,
LD31-S401, LD31-S411, LD31-S421, LD31-S431,
LD32-S301, LD32-S311, LD32-S321, LD32-S331
LD32-S401, LD32-S411, LD32-S421 & LD32-S431
Series

2 of 13 DeltaSpan (IS) LD31 / LD32 Series 31 MAR 11
MN301031 Rev C
Preface
This manual explains how to use the Intrinsically Safe DeltaSpan LD31 submersible series & LD32 waste water
series pressure level transmitter.
Warranty, Service & Repair
To register your product with the manufacturer, go to the Flowline website for on-line registration. The website
address is as follows:
www.flowline.com
On-line Warranty Registration can be found under Customer Support in the Navigation Bar along the side of the
home page.
If for some reason your product must be returned for factory service, go to the Flowline website to receive a
Material Return Authorization number (MRA), providing the following information:
1. Full Part Number, Full Serial Number
2. Name and telephone number of someone who can answer technical questions related to the product
and its application.
3. Return Shipping Address
4. Brief Description of the Symptom
5. Brief Description of the Application
On-line Material Return Authorization can be found under Customer Support in the Navigation Bar along the
side of the home page. Click on Customer Return to begin the MRA request. Once you have received a MRA
number, ship the product prepaid in its original packing to:
Flowline Factory Service
MRA_____
10500 Humbolt Street
Los Alamitos, CA 90720
To avoid delays in processing your repair, write the MRA on the shipping label. Please include the information
about the malfunction with your product. This information enables our service technicians to process your
repair order as quickly as possible.

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 3 of 13
Rev C MN301031
Warranty
Flowline warrants to the original purchaser of its products that such products will be free from defects in
material and workmanship under normal use and service in accordance with instructions furnished by Flowline
for a period, which is equal to the shorter of one year from the date of purchase of such products or two years
from the date of manufacture of such products. Flowline's obligation under this warranty is solely and
exclusively limited to the repair or replacement, at Flowline's option, of the products or components, which
Flowline's examination determines to its satisfaction to be defective in material or workmanship within the
warranty period. Flowline must be notified pursuant to the instructions below of any claim under this warranty
within thirty (30) days of any claimed lack of conformity of the product. Any product repaired or replaced
under this warranty will be warranted only for the remainder of the original warranty period.
Returns
Products cannot be returned to Flowline without Flowline's prior authorization. To return a product that is
thought to be defective, go to www.flowline.com, and submit a customer return (MRA) request form and follow
the instructions therein. All warranty and non-warranty product returns to Flowline must be shipped prepaid and
insured. Flowline will not be responsible for any products lost or damaged in shipment.
Limitations
This warranty does not apply to products which: 1) are beyond the warranty period or are products for which
the original purchaser does not follow the warranty procedures outlined above; 2) have been subjected to
electrical, mechanical or chemical damage due to improper, accidental or negligent use; 3) have been modified
or altered; 4) anyone other than service personnel authorized by Flowline have attempted to repair; 5) have
been involved in accidents or natural disasters; or 6) are damaged during return shipment to Flowline. Flowline
reserves the right to unilaterally waive this warranty and dispose of any product returned to Flowline where: 1)
there is evidence of a potentially hazardous material present with the product; or 2) the product has remained
unclaimed at Flowline for more than 30 days after Flowline has dutifully requested disposition. This warranty
contains the sole express warranty made by Flowline in connection with its products. ALL IMPLIED
WARRANTIES, INCLUDING WITHOUT LIMITATION, THE WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY DISCLAIMED. The remedies of
repair or replacement as stated above are the exclusive remedies for the breach of this warranty. IN NO EVENT
SHALL FLOWLINE BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY
KIND INCLUDING PERSONAL OR REAL PROPERTY OR FOR INJURY TO ANY PERSON. THIS
WARRANTY CONSTITUTES THE FINAL, COMPLETE AND EXCLUSIVE STATEMENT OF
WARRANTY TERMS AND NO PERSON IS AUTHORIZED TO MAKE ANY OTHER WARRANTIES OR
REPRESENTATIONS ON BEHALF OF FLOWLINE. This warranty will be interpreted pursuant to the laws
of the State of California. If any portion of this warranty is held to be invalid or unenforceable for any reason,
such finding will not invalidate any other provision of this warranty.

4 of 13 DeltaSpan (IS) LD31 / LD32 Series 31 MAR 11
MN301031 Rev C
Introduction
The LD31 / LD32 series Intrinsically Safe DeltaSpan Submersible / Waste Water Level Transmitters are
manufactured for years of trouble free service in the harshest applications. The pressure transmitter measures
the height of liquid above the position in the tank referenced to atmospheric pressure. The transmitter consists
of a piezoresistive sensing element, encased in 316 SS housing. The LD31 series features a bullet nose design
protects the diaphragm from damage.
Superior lightning and surge protection utilizing dual arrestor technology, grounded to case, eliminating both
power supply surges and lightning ground strike transients. Large diameter 316 SS diaphragm seal is non-
clogging and damage resistant to floating solids.
The transmitter is equipped with a 270-pound tensile strength shielded and vented cable. Ventilation tube in the
cable automatically compensates for changes in atmospheric pressure above the tank. The vent is protected
with a maintenance free filter eliminating particulate or water droplets from entering the transducer.
Excellent chemical compatibility with 316 construction
Lightning and surge protection on all models
Maintenance free vent filter
LD31 series features slim design for tight applications
LD32 series features large diameter, non-clogging, damage resistant, 316 SS diaphragm seal
Table of Contents
Introduction ..........................................................................................................................4
About this Manual................................................................................................................5
Components .........................................................................................................................6
Technology ..........................................................................................................................6
Specifications .......................................................................................................................7
Dimensions ..........................................................................................................................8
Material Compatibility .........................................................................................................8
Getting Started .....................................................................................................................8
How to convert Pressure into Liquid Height?..........................................................9
How does Specific Gravity affect pressure transmitters? ........................................9
How to select the correct pressure transmitter? .....................................................10
Electrical Installation .........................................................................................................10
Wiring – Control Drawing .....................................................................................11
Installation..........................................................................................................................12
Interference ............................................................................................................12
Termination ............................................................................................................12
Maintenance .......................................................................................................................12
Testing the transmitter ...........................................................................................13

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 5 of 13
Rev C MN301031
About this Manual:
PLEASE READ THE ENTIRE MANUAL PRIOR TO INSTALLING OR USING THIS PRODUCT. This
manual includes information on all versions of the DeltaSpan Series Pressure Level Transmitter from Flowline;
models LD31-S3__, LD31-S4__, LD32-S3__ and LD32-S4__. Please refer to the part number located on the
transmitter label to verify the exact model which you have purchased.
User’s Responsibility for Safety:
Flowline manufactures a wide range of liquid level sensors and technologies. While each of these technologies
are designed to operate in a wide variety of applications, it is the user’s responsibility to select a technology that
is appropriate for the application, install it properly, perform tests of the installed system, and maintain all
components. The failure to do so could result in property damage or serious injury.
Proper Installation and Handling:
Only properly-trained staff should install and/or repair this product. Use a proper sealant with all installations.
Always check for leaks prior to system start-up.
Wiring and Electrical:
CAUTION: Do not exceed specified supply voltage ratings. Permanent damage not covered by warranty will
result. This device is not designed for 120 or 240 volt AC operation. Use only on 10 to 28 VDC.
Temperature and Pressure:
The LD31 and LD32 series are designed for use in application temperatures from -18° to 80°C (0° to 176°F).
Both series are designed for use at pressures up to 2 x the full span.
Material Compatibility:
Both series are made of 316 Stainless Steel (316 SS), 316L Stainless Steel (316L SS) with a cable of
Polyurethane or Ethylene Tetrafluoroethylene (ETFE). The LD31 series has a bullet nose of Polyvinyl Chloride
(PVC). Make sure that the model which you have selected is chemically compatible with the application
liquids.
Flammable, Explosive and Hazardous Applications:
The LD31 / LD32 series is UL listed for use in Hazardous (Classified) Locations. The protection method is by
Intrinsic Safety, “ia”. It was investigated by UL under UL Standard 913 Sixth Edition and CSA Standard No.
157-92.
For use in Hazardous (Classified) Locations: Class I Div. 1 Groups A,B,C,D; Class II Div. 1 Groups E,F,G;
Class III Div. 1; Temperature Code: T4 @ 80°C ambient; Install in accordance with control drawing 01-
700797-00.

6 of 13 DeltaSpan (IS) LD31 / LD32 Series 31 MAR 11
MN301031 Rev C
Make a Fail-Safe System:
Design a fail-safe system that accommodates the possibility of transmitter failure or battery power loss. In
critical applications, Flowline recommends the use of redundant backup systems and alarms in addition to the
primary system.
Components:
DeltaSpan is offered in eight different models, based upon pressure rating and material. Depending on the
model purchased, you may or may not have been shipped all the components shown below. .
DeltaSpan
oLD31-S301 – 05 psi (11.54 ft wc / 3.52 m wc), 40’ (12.2 m) Polyurethane Cable
oLD31-S311 – 10 psi (23.09 ft wc / 7.04 m wc), 40’ (12.2 m) Polyurethane Cable
oLD31-S321 – 15 psi (34.63 ft wc / 10.56 m wc), 60’ (18.3 m) Polyurethane Cable
oLD31-S331 – 20 psi (46.18 ft wc / 14.08 m wc), 60’ (18.3 m) Polyurethane Cable
oLD31-S401 – 05 psi (11.54 ft wc / 3.52 m wc), 40’ (12.2 m) ETFE Cable
oLD31-S411 – 10 psi (23.09 ft wc / 7.04 m wc), 40’ (12.2 m) ETFE Cable
oLD31-S421 – 15 psi (34.63 ft wc / 10.56 m wc), 60’ (18.3 m) ETFE Cable
oLD31-S431 – 20 psi (46.18 ft wc / 14.08 m wc), 60’ (18.3 m) ETFE Cable
oLD32-S301 – 05 psi (11.54 ft wc / 3.52 m wc), 40’ (12.2 m) Polyurethane Cable
oLD32-S311 – 10 psi (23.09 ft wc / 7.04 m wc), 40’ (12.2 m) Polyurethane Cable
oLD32-S321 – 15 psi (34.63 ft wc / 10.56 m wc), 60’ (18.3 m) Polyurethane Cable
oLD32-S331 – 20 psi (46.18 ft wc / 14.08 m wc), 60’ (18.3 m) Polyurethane Cable
oLD32-S401 – 05 psi (11.54 ft wc / 3.52 m wc), 40’ (12.2 m) ETFE Cable
oLD32-S411 – 10 psi (23.09 ft wc / 7.04 m wc), 40’ (12.2 m) ETFE Cable
oLD32-S421 – 15 psi (34.63 ft wc / 10.56 m wc), 60’ (18.3 m) ETFE Cable
oLD32-S431 – 20 psi (46.18 ft wc / 14.08 m wc), 60’ (18.3 m) ETFE Cable
Quick Start Guide
Technology
A sealed pressure transmitter is placed near or on the bottom of the tank. A stainless steel pressure diaphragm
within the pressure transmitter is exposed on one side to the application liquid. The other side is exposed to the
reference pressure via a small ventilation tube located inside of the Polyurethane cable. A difference in pressure
between liquid and reference pressures will slightly deflect the diaphragm. The deflection of the diaphragm is
measured by a built-in microprocessor that provides greater linearity correction over common thermal
compensation methods. A 4-20 mA current signal proportional the height of the liquid is generated from the
microprocessor.

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 7 of 13
Rev C MN301031
Specifications
Service: Compatible liquids
Wetted Materials: Body: 316 SS, 316L SS and Buna-N
Cable: Polyurethane or ETFE
Bullet Nose: PVC (LD31 series only)
Accuracy: ±0.25% of full scale
Temperature Limit: 0 to 176°F (-18 to 80°C)
Compensated Temperature Range: 0 to 176°F (-18 to 80°C)
Thermal Effect: Less than ±0.02%/°F
Pressure Limit: 2X full scale
Power Requirement: 10 to 28 VDC
Output Signal: 4 to 20 mA DC, 2-wire
Response Time: 50 ms
Max. Loop Resistance: 900 ohms
Electrical Connections: Wire pigtail
Cable Length: -__01/-__11: 40’ (12.2 m)
-__21/-__31: 60’ (18.3 m)
Mounting Orientation: Suspended in tank below level being measured -
Can be placed on the bottom of the tank on its side
Weight: 2.2 lb (1.0 kg) – (LD31 series)
4.3 lb (2.0 kg) – (LD32 series)
Agency Approvals: CE, UL Intrinsically Safe to UL Standard 913. (See Intrinsic Safety
Approval Classification.)
The following standards were used for CE approval:
IEC 61000-4-2: 2001
IEC 61000-4-3: 2006
IEC 61000-4-4: 2004
IEC 61000-4-5: 2005
IEC 61000-4-6: 2006
IEC 61000-4-8: 2001
CENELEC EN 55011: 2003
CENELEC EN 61326: 2003
89/336/EEC EMC Directive
WARNING: To prevent ignition of flammable or combustible atmospheres, disconnect power before
servicing. Use with approved safety barriers using entity evaluation.
Series
Vmax
Imax
Ci
Li
Pi
LD31
26 VDC
93 mA
0.051 uF
240 uH
0.651 W
LD32
28 VDC
93 mA
0.051 uF
240 uH
0.651 W
WARNING: Do not exceed specified supply voltage ratings. Permanent damage not covered by
warranty will result. This device is not designed for 120 or 240 volt AC operations. Use only on 10 to 28
VDC.

8 of 13 DeltaSpan (IS) LD31 / LD32 Series 31 MAR 11
MN301031 Rev C
Dimensions:
LD31 Series:
LD32 Series:
Material Compatibility:
oThe LD31 / LD32 series is made of 316 Stainless Steel (316 SS), 316L Stainless Steel (316L SS) with
a cable of Polyurethane or Ethylene Tetrafluoroethylene (ETFE). The LD31 series has a bullet nose of
Polyvinyl Chloride (PVC).
oMake sure that the switch is compatible with the application liquids. To determine the chemical
compatibility between the sensor and its application liquids, refer to the Compass Corrosion Guide,
available from Compass Publications (858-589-9636).
Getting Started
Pressure transmitters are designed to be submersed within the application fluid. The transmitters can either rest
along the bottom of the tank or be suspended at any desired level within the tank. Please note that the physical
location of the level transmitter will indicate the lowest level of measurement within the tank. For example:
mounting the transmitter 1 foot from the bottom of the tank, then the lowest reading of liquid will be 1 foot
from the bottom.

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 9 of 13
Rev C MN301031
How to convert Pressure into Liquid Height?
Pressure transmitters are all describe by the pressure range and not by liquid height. To convert pressure liquid
height, use the following ratio:
1 psi = 2.31 feet of water
or
1 psi = 0.704 meters of water
Therefore, a 15 psi transmitter will have a liquid height = 34.65 feet (10.56 m) or [15 psi x 2.31’/psi = 34.65’ or
(15 psi x 0.704 m/psi = 10.56 m)]. With the above ratio, you can always find the liquid height or water column
(wc) of any pressure transmitter.
How does Specific Gravity affect pressure transmitters?
The Specific Gravity (SG) of a liquid will not change the pressure of the transmitter, but will affect how the
transmitter reads the liquid height.
Water has a SG = 1.0.
A SG less than 1.0 will result in an increase in the liquid height the pressure transmitter.
A SG greater than 1.0 will result in a decrease in the liquid height the pressure transmitter.
To calculate the Maximum Liquid Height, use the following formula:
Maximum Liquid Height (feet) = (Pressure Range x 2.31) / SG
or
Maximum Liquid Height (meters) = (Pressure Range x 0.704) / SG
For example, 15 psi transmitter installed in a liquid with a SG=0.9 will have a Maximum Liquid Height = 38.5
feet (11.73 m) or [(15 psi x 2.31’/psi)/ 0.9 = 38.5’]. Notice how the above formula will always provide the
Maximum Liquid Height for any pressure transmitter.
Compare the Maximum Liquid Height of a liquid with a SG = 0.9 to one with a SG = 1.0.
SG = 0.9: a 15 psi transmitter will have a Maximum Liquid Height = 38.5’ (11.73 m)
SG = 1.0: a 15 psi transmitter will have a Maximum Liquid Height = 34.65’ (10.56 m)
A change in SG of 0.1 will increase the Maximum Liquid Height of a transmitter by 3.83’ (1.2 m). Thus, when
the Specific Gravity is less than 1.0, the Maximum Liquid Height of the transmitter will increase.
The reverse is true by increasing the Specific Gravity. With a SG = 1.2, the Maximum Liquid Height = 28.88’
(8.80 m) with a 15 psi transmitter
Maximum Liquid Height (28.88’) = (Pressure Range (15 psi) x 2.31) / SG (1.2)
Compare to a liquid with a SG = 1.0, the Maximum Liquid Height will decrease by 5.77’ (1.8 m). When the
Specific Gravity is greater than 1.0, the Maximum Liquid Height of the transmitter will decrease.

10 of 13 DeltaSpan (IS) LD31 / LD32 Series 31 MAR 11
MN301031 Rev C
How to select the correct pressure transmitter?
The objective is to use a pressure transmitter that will cover the entire range of the application. If the liquid
height of the tank is above the transmitter’s Maximum Liquid Height, then the sensor will not be able to read
the level of a full tank. Compare the tanks Required Maximum Pressure against the transmitter’s pressure to
select a sensor.
To calculate the Required Maximum Pressure of the tank, use the following formula:
Required Maximum Pressure = [Full Tank Height (feet) x SG] / 2.31 (feet/psi)
or
Required Maximum Pressure = [Full Tank Height (meters) x SG] / 0.704 (m/psi)
To select the correct pressure transmitter, follow the steps below:
1. Measure the height of a full tank (Full Tank Height)
2. Determine the SG for the liquid (if the customer does not know, check the MSDS sheet)
3. Use the formula above to calculate the Required Maximum Pressure
a. Ex: A 40’ tank with a liquid media SG of 0.9 requires a pressure transmitter with what PSI to
measure tank range of 40’?
b. [(40’ x 0.9) / 2.31’/psi] = 15.58 psi
4. Select a pressure transmitter with a pressure greater than or equal to the Required Maximum Pressure.
a. In the example above, use a transmitter with a psi greater than or equal to 15.58 psi
b. A transmitter with a range of 20 psi will be able to read the entire range of the tank.
c. A transmitter with a range of 15 psi will be short 0.58 psi or (1.48’).
Electrical Installation
Wire Length - The maximum length of wire connecting the transmitter and receiver is a function of wire size
and receiver resistance. Wiring should not contribute more than 10% of the receiver resistance to total loop
resistance. For extremely long runs (over 1000 feet), choose receivers with higher resistance to minimize the
size and cost of connecting leads. Where wiring length is under 100 feet, wire as small as 22 AWG can be used.
Wiring - An external power supply delivering 10-28 VDC with minimum current capability of 40 mA DC (per
transmitter) is required to power the control loop. See Fig. A for connection of the power supply, transmitter
and receiver. The range of appropriate receiver load resistance (RL) for the DC power supply voltage available
is expressed by the formula:
RLmax = (Vsup – 10V) / 20 mA DC
Shielded cable is recommended for control loop wiring. Use the Red wire as the (+) and the Black wire as
the (-).
Black wire is negative (-) and red wire is positive (+).

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 11 of 13
Rev C MN301031
Wiring –Control Drawing
Wiring to a Loop Powered Display (refer to Control Drawing above)
Wiring to a Typical PLC (refer to Control Drawing above)

12 of 13 DeltaSpan (IS) LD31 / LD32 Series 31 MAR 11
MN301031 Rev C
Installation
The LD31 / LD32 series is designed to operate while submerged in the actual application
liquid. Avoid installing the level transmitter along the bottom of the tank is materials
such as sludge will build up and coat/cover the transmitter. This also includes any debris
that will settle along the bottom of the tank. In these applications, it is best to suspend
the transmitter above the highest level of sludge/debris that will occur.
1. Location: Select a location where the temperature of the transmitter will be
between 0 and 176°F (-18 to 80°C). Distance from the receiver is limited only by total loop resistance.
2. Position: The transmitter is not position sensitive. However all standard models are originally calibrated
with the unit in a position with the pressure connection downward. Although they can be used at other
angles, for best accuracy it is recommended that units be installed in the position calibrated at the
factory.
3. Mounting: The transmitter can be mounted via several methods. It can be suspended from the electrical
cable, it can be placed resting on the bottom of the tank in either horizontal or vertical orientation, or it
can be attached to a pipe or hang wire by the 1/2˝ NPT male connection on the top of the housing.
Interference
The DeltaSpan is designed to operate under the surface of the liquid in the tank. Avoid
installations where other tank requirements will cause the transmitter to move or swing.
For example: a mixer blade could cause the level transmitter to whip around within the
tank. An alternative would be to move the transmitter to a more stable section of the tank
or to install the LD31 series inside a still well/drop tube. The still well/drop pipe will
minimize the effects created by the mixer.
Termination
The cable for the DeltaSpan is typically terminated at a junction box located on top of the
tank. Since the vent tube is contained within the cable, the pressure within the junction box
must always be the same as the reference (typically atmospheric) pressure for the liquid.
The inside of the junction box must be clean, dry and free of moisture. Add the optional
pressure fitting (LD90-_001) to complete the package. The LD90-_001 features a 2” NPT
thread for mounting and a liquid tight connector to seal the cable interface.
Note: Use caution when sealing the cable at the top of the tank. The ventilation tube must
be open and free to allow air to flow back to the pressure diaphragm. Avoid blocking the
ventilation tube by compressing the cable. Always keep the cable termination clean, dry
and free of moisture and prevent liquid from entering the vent tube.
Maintenance
After final installation of the pressure transmitter and its companion receiver, no routine maintenance is
required. A periodic check of system calibration is suggested. The pressure transmitters are not field repairable
and should be returned if repair is needed (field repair should not be attempted and may void warranty). Be sure
to include a brief description of the problem plus any relevant application notes. Contact customer service to
receive a return goods authorization number before shipping.
Maintenance should consist of inspection to see that the transmitter is free from debris and not coated with any
substance, which would prevent liquid from freely entering and leaving the transmitter. If this occurs, the
transmitter should be cleaned.

31 MAR 11 DeltaSpan (IS) LD31 / LD32 Series 13 of 13
Rev C MN301031
Testing the transmitter:
Verify proper wiring, power supply and loop resistance. If transmitter is not functioning properly, isolate the
transmitter from the system and wire as shown below. Be sure to remove the sensor from the classified area
when performing this test. Multimeter should read 4 mA with the transmitter out of liquid.