Pitot tube deltaflow - an engineering approach systec Controls Meß- und Regeltechnik GmbH

Industrial Flowmeters

Pitot tube deltaflow -

an engineering approach

systec Controls Meß- und Regeltechnik GmbH

Sebastian Fischer

Sales Manager


Agenda

1. Design your deltaflowSelect your deltaflow, deltaflow types, calculation software deltacalc, Mounting, Required Parameters, dp-connection, opposite support

2. Bidirectional Measurement

3. Splitting Range

4. How to handle polluted media - Air purging system LSP

5. deltaflow for high-pressure applications – DF25HDD3

6. How to calibrate your deltaflow

7. Straight run requirements

8. Using integrated temperature & pressure measurement


Chapter 1 - Design your deltaflow

This chapter contains:

• What deltaflow types are available?

• What parameters do I have to know?

• What minimum dp should I have for reliable measurement?

• How can I handle low flows?

• How can I handle big measurement ranges (span)?

• How does a bi-directional measurement look like?


Design your deltaflow – deltaflow series

Type Pipe Size Pressure Remarks

DF8 1-25mm 0-690bar Spool piece with integrated orifice

DF10 DN20-DN100 0-690bar Basically replaced by DF12

DF12 DN20-DN100 0-160bar

DF25 DN65-DN2500 0-PN160 (PN250)

DF25 Quick-lock DN65-DN2500 0-100bar Retractable

DF44 200mm-15m 0-100bar

DF25HDD3 60-690bar 0-690bar weld-in (high-pressure)

DF8 DF12 DF25 DF25HDD3 DF25 Quicklok DF44


What process connections / types are available?

Design your deltaflow – deltaflow types


Flange-type

Cut-Ring Type



Spool Piece Weld-in (DF25HDD3) Weld-in (DF12)



DF8 – spool piece (block) with integrated orifice

DF25 Quick-lock system allows mounting/extraction under pressurized conditions (max. 100bar)



DF8 DF12 DF25

DF25HDD

3

DF44 Remarks

Flange-stud X X X Max. PN250(PN160 for steam)

Cut-Ring X X Max. PN40

Weld-in X X

Quick-lock o.r. X Max. 100bar

Spool Piece X X X X max DN250 (other o.r.)

deltaflow types - Summary

Note: Spool Pieces are available with welding ends or flanges


Design your deltaflow – required parameters (1)

Profile crosses whole diameter -> length customized to application

• Internal Diameter ID

• Wall thickness WT

• Thickness of isolation IT

are required

WT

ID

Insulation IT

Stud (e.g. cut ring or flange)

dp-connection

Profile



Profi

le

Neck

Material Designation

1.4571 (SS316Ti) Stainless Steel, Standard Material (>>90% of all applications), up to 500°C

1.4828 High-temperature applications (up to 1040°C)

1.4539, Hastelloy C4, Haynes Alloy

corrosive media

High-pressue See seperate chapter

• In most cases neck and parts outside of the pipe can be made of standard SS316 (1.4571) also when profile is made of special material• Material of weld-in stud should be equal or similar to pipe material



Pipe Data

• Wall thickness

• Internal Diameter

• Pipe Material

• Orientation of Pipe (horizontal or vertical

Process

• Flow

• Temperature

• Pressure


Calculate (design) your deltaflow – calculation software deltacalc ?

..\..\..\..\Program Files\deltacalc 7\deltacalc7PRO.exe


How can I connect my deltaflow with my dp-transmitter ?


Design your deltaflow - Mounting of dp-transmitter

Direct Mounting

Remote Mounting


dp-Connection - 3-way-manifold

direct+ Easy setting of zero point by using by-pass+ Shut-off of media (e.g. allows remove of transmitter)+ high pressure / temperature (PN400)

- Smaller internal piping -> not recommended for wet gases


dp-Connection – Ball Valves

Direct

+ Shut-off of media (e.g. allows remove of transmitter) possible

+ big opening -> recommended for wet/dirty gases (e.g. Biogas)

+ Available with threads, welding ends, oval adapters, fittings (ermeto,..)

- Limited concerning Temperature/Pressure (70bar at 35°C, 2 bar at 200°C)

Remote


dp-Connection – Shut-off valves

Needle (shut-off) Valves (normally for remote installation of transmitter)

• Double (see pic.) and single valves available

•Available with welding ends, thread, Ermeto, Swagelok. Customized connections possible

+ Shut-off of media (e.g. allows remove of transmitter)

+ big opening + High pressure/temperature (PN400)


dp-Connection – Miscellaneous

Fitting (e.g. Ermeto) for remote mounting

Ball Valve with fitting (e.g. Ermeto) for remote mounting

Oval Adapter (direct mounting)(acc. to EN61518)

Welding Ends for remote mounting


dp-Connection – Miscellaneous (2)

Weather Protection Box

+ provides heating and protection for electrical equipment (transmitters)+ Can be mounted remotley or direct on deltaflow‘s flange


dp-Connection – Summary

• Various possibilities of connections of dp-transmitters are available

• Possibility to shut-off connection to media (valves) is recommended

• If not specified by customer we recommend 3-way-manifold or ball valve (wet / dirty gases) for standard applications

• When using high-pressure equipment double valves are recommended


How should I mount my deltaflow?


Mounting – Liquid Service

• Mounting should allow gas bubbles to vent off

• When installed sidewards probe should be slightly slanted (-3…0°)


Mounting – Gas Service

• Mounting should allow condensate to drain back into pipe

(Otherwise condensate might accumulate in internal piping and generate water column (which generates faulty dp))

• When installed sidewards probe should be slightly slanted (0..3°)


Mounting – Steam Service

• Condensate is used to transmit dp to transmitter

• Mounting should allow excessive condensate to drain back into pipe

• When installed sidewards probe should be slightly slanted (0..3°)


Design your deltaflow – Required dp

deltaflow requires a minimum differential pressure to ensure reliable measurement:

As rule of thumb you should have at least:

• Gases / Liquids: >0.2mbar @ Qmin

• Steam: >5mbar (steam applications are more sensitive against misinstallation than gas / liquids) @ Qmin

dp‘s can be calculated for each application by using deltacalc software


Design your deltaflow – required dp

How can I handle low flows?

• Sometimes velocity is too low to provide sufficient dp values

• Spool Pieces with reduction can be used to speed up mediaReduction

(e.g. DN100/DN65)

Widening (e.g. DN65/DN100

By using spool pieces with reduction deltaflow can serve also typical low flow applications (e.g. Biogas)


What‘s about the mechanical stability of deltaflow?

When do I need an opposite support ?

Design your deltaflow – opposite support


Opposite Support - Background

Probe has a specific resonance frequency (RF) depending on length and width of probe

Flow generates Vortex („turbulence“) with a specific frequency (VF) at probe depending on velocity and width of probe („probe is stimulated“)[RF and VF are mentioned at deltacalc calculation protocol]

If Vortex frequency = resonance frequency (or multiple) probe might resonate and might break!

To ensure mechanical stability an opposite support might be required

Vortex


Frequency calculation without opposite supportApplication: Steam, DN200, 7bar, 200°C, various flows, without opposite support

v=7.73m/s v=24.58m/s v=61.46m/s

RF VF SF VF SF VF SF

DF25 248.9 70,2 3,55 234,1 1,06 585,3 0,43

DF32 264.5 43,8 6,04 145,9 1,81 364,7 0,73

DF44 383.3 33,5 11,44 111,7 3,43 279,4 1,37

RF = Resonance Frequency of Probe / VF=Vortex Frequency

Saftey Factor SF = RF/VF

SF should be >= 1.3 to ensure mechanical stability


Application: Steam, DN200, 7bar, 200°C, various flows, with opposite support

v=7.73m/s v=24.58m/s v=61.46m/s

RF VF SF VF SF VF SF

DF25 995,8 70,2 14,19 234,1 4,25 585,3 1,7

DF32 1058,0 43,8 24,16 145,9 7,25 364,7 2,9

DF44 1535,2 33,5 45,83 111,7 13,74 279,4 5,49

Opposite Support quadruples Resonance Frequency and Saftey!

The bigger the profile the higher the resonance frequency

Frequency calculation with opposite support


Opposite Support – Examples

High-pressure probe withopposite support

DF25 prepared for use with (upper) and without (lower) opposite support


Opposite Support – Summary / Design RulesOpposite Support Required if:

• Pipe Size >= DN1000

• dp >= 20mbar and RF/VF <= 1.3

• High-pressure probe

Check (if required or not) is done automatically by deltacalc (except because of size!)


Chapter 2 – Splitting Range Measurement

How can I handle big measurement ranges?


Splitting range

• deltaflow offers a span of typically 1 to 7..10

• 1 to 10 in flow means 1 to 100 (!) in dp

How does that influence my measurement?

Example: dp_min = 2mbar / dp_max = 240mbarspan dp-transmitter: 250mbar, uncertainty 0.1% (=0.25mbar)

0.25mbar at 2mbar means relative uncertainty of 12.5%

With splitting range. e.g:

1. Transmitter: 0…20mbar

2. Transmitter: 20…240mbar


Design your deltaflow – splitting range

How can I realize a splitting range measurement?

• You need two (or more) (stacked) transmitters

• You need evaluation unit (e.g. flowcom or PCS) which decides which transmitter should be used (depending on dp)

Connectors („T-bone“)


Splitting range - summary

• With splitting range up to 4 dp-transmitters can be used

• Span of 1..30 and more can be realized(pay attention to mechanical stability)


Chapter 3 – Bi-directional Measurement


Bi-directional measurement

Flow (splitting range)Back Flow

(splitting range)

• Thanks to symetrical profile deltaflow can measure bidirectional

• Each direction requires it‘s own transmitter(s)

• Flowcom (or PCS) controls measurement


When do I need an air purging system (LSP)

Chapter 4 – Air purging


Air purging system LSP

• Highly Polluted media might clog deltaflow‘s dp-tappings

• When dust-load >=50mg/m3 automatical cleaning is required

• systec offers automatic air purging system LSP for periodical cleaning

• LSP blows pressurized air into deltaflow pressure chambers


Air purging system LSP - Principle

Connections for dp-impulse pipes (Ermeto, others on request)

Connection for pressurized air (max. 6bar)

Valves: When purging connection to dp-transmitter is closed and connection to pressurized air is open

Purging is controlled by SPS. Frequency of purging as well as length of purging can be set by user

dp-transmitter can be mounted directly on LSP by using mounting plate


Air purging system LSP - Example

Connected by impulse piping

LSP with mounted dp-transmitter

Shut-off (ball valves)

deltaflow DF50 (old style), flange type


Air purging system LSP - Summary

• With LSP measurements at high degrees of pollution (up to 200 g/m3 (!)) become possible

• During purging dp is hydraulically locked -> no lost of dp-signal during purging

• Option „Signal holding“ available. Here, last value of dp before purging is holded electronically by SPS

• Direct mounting of dp-transmitter possible (on top of LSP)

• Pressurized Air required on site (max. 6 bar)

• Impulse piping required (LSP - deltaflow)


When do I need a high-pressure probe and what‘s about it ?

Chapter 5 – deltaflow for high-pressure applications


High pressure probe

When do I need high pressure probe?

• Limits for standard DF25: PN160 (steam), PN250 (Liquids)

Finally, it has to be determined by customer, but there are indications when to use high-pressure probe:

• When weld-in probe is required (e.g. sealings are not accepted)

• When pipe is made of high grade material (e.g. P91, 10CrMo 9 10))


High pressure probe

For high pressure applications a special version of the DF25 (DF25HDD3) is available

• Profile made of massive block (no welding seams)

• Material of Profile: 1.4828

• Materials of weld-in parts:16Mo3, 10CrMo 9 10, P91

• Material of valves:16Mo3, 10CrMo 9 10

• opposite support always required

Profile

Weld-in part („neck)

Condensate Pots (for steam only)

Double valves


High pressure probe - Examples

- Steam, 535°C, 190bar - spool piece- Profile: 1.4828- Weld-in part: P91- Condensate Pots: P91

- Steam, 540°C, 100bar - Profile: 1.4828- Weld-in part: 10 CrMo9 10- Condensate Pots:10 CroMo 9 10 (=1.7380)


High pressure probe – Required certificates / testings

Requirements are regulated by PED97/23/EG

16 Mo 3(1.5415)

13CroMo44(1.7335)

10CrMo9 10(1.7380/1.7383)

X20CrMoV12 1(1.4922)

P91(1.4903)

X-Ray X

TÜV acceptance test (dye penetration, hardness test, material identification check)

x x x x X

Heat treatment

x x x x

Documentation incl. 3.2 certificate

x x x x x


Chapter 6 – Calibration


Calibration

dpdqm 2²4

1 Formula for flow calculation

• During calibration flow, dp (at deltaflow), p, T are measured at different points

• Corrected Blockage Factor Zeta is extracted

• Corrected Zeta will be then used for your appliaction

-> Improved accuracy (0.4%)

• Calibration can be done at PtB or at systec

• Spool Piece always required

• PtB or systec issue calibration certificate


Factory Certificate

PtB Certificate


Chapter 7 - Straight run requirements

What is the best mounting position for my deltaflow?


Straight run requirements


Straight run requirements - ImproveIT

•ImproveIT is a data base which offers calibration factors for typical obstacles in inlet (curves)

• Factors are provided by systec on request

• Factors can be put into deltacalc


Chapter 8 – Integrated pressure and temperature measurement

Why could p/T-compensation improve the accuracy?

How does it look like?


Integrated pressure/temperature measurement - background

dpdqm 2²4

1Density, depends on pressure (p) and Temperature (T)

• If pressure and/or temperature change, density also changes

• Density influences flow (e.g. T +10% -> density +10% -> q +srt(10%)=3.16%

• To compensate influence, p and/or T should be measured in order to calculate correct density (flowcom / multi variable transmitter)

• Only recommended/required when p and/or T fluctuate


Flowcomputer flowcom

• p&T compensation + Mass flow calculation

• Heat transfer measurement

• Data Logger + Display

• Easy handling (on-site with buttons)


Integrated pressure/temperature measurement

Integrated PT100

- Can be removed under pressurized conditions- 0…400 (600°C)- direct PT100 or 4…20mA (with transmitter)

Cable Box

Presseure measurement(here: Steam Service)

- Can be removed under pressurized Conditions (when having valve)- direct PT100 or 4…20mA


Integrated pressure/temperature measurement - Examples

DF44 with preparation for external pressure transmitter (supplied by customer)

(here: Liquid Service)

DF12 with spool piece, integrated temperature measurement(Gas Service)


Integrated pressure/temperature measurement - Examples

DF10 with integratedtemperature (Gas Service)

DF8 with preparation for pressure measurement (Gas Service)

DF8 with preparation for pressure measurement (Steam Service)


Integrated pressure/temperature measurement

Model Integrated pressure

Integrated Temperature

DF8 X X Integrated in spool piece

DF10 X X Integrated in spool piece

DF12 (x) (x) Only with spool piece

DF25 X X

DF25HDD3

DF44 X X


References

• deltaflow Data Sheets

• deltacalc calculation software

• deltaflow manual

• flowcom manual

• LSP manual

Date post:	08-Jan-2016
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Pitot tube deltaflow - an engineering approach systec Controls Meß- und Regeltechnik GmbH

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