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Mechanical Agitators | Rotating Equipment Engineering

1 Purpose
2 References 2.1 SABIC Engineering Standards (SES) 2.2 American Society of Mechanical Engineers (ASME)
3 Addenda Section 4 – Design and Manufacture

4.1 General 4.2 Materials 4.3 Agitation Assemblies 4.4 Steady Bearing 4.5 Shaft Sealing System 4.7 Shaft Couplings and Guards 4.8 Gear Reducer 4.9 Drive Motor
Section 6 – Testing 6.3 Optional Tests

1 Purpose

Process Industry Practice PIP # RES M001 Rev.97 is adopted as a SABIC Engineering Standard
with the following addenda.
2 References
Reference is made in this addendum to the following documents. The latest issue, amendments
and supplements of these documents shall apply, unless otherwise indicated.
2.1 SABIC Engineering Standards (SES)
2.1.1 E06-S01: Induction Motors 150 kW and below (IEC)
2.1.2 E06-S02: Induction Motors 150 kW and above (IEC)
2.1.3 Q01-E01: Pressure Vessels – General
2.2 American Society of Mechanical Engineers (ASME)
2.2.1 BPVC Section IX Rev.07: Welding and Brazing Qualifications
3 Addenda
The following section, subsection, paragraph numbers refer to PIP RES M001, May 1997.
Section 4 – Design and Manufacture
4.1 General
4.1.3 Add the following paragraph:
The following design criteria shall be used for agitators.
a. Replacement of bearings, shaft sealing devices, gear unit, and driver shall be possible
without dismantling other major parts of the unit, and without emptying or depressurizing
the vessel.
b. Connection of the drive shaft to the agitator shaft shall be outside the pressure vessel.
c. All support rod turnbuckles shall have locknuts.
d. The agitator shall preferably be furnished as a single unit, ready for installation on
vessel/tank mounting flange without requiring the alignment of parts.
4.1.7 Add the following sentence:
For pressure vessel mechanical design details, see SES Q01-E01.
4.1.10 Add the following paragraph:
Vendor shall conform to sound pressure level control requirements. Unless otherwise specified,
the maximum sound level shall be 85 dBA at 1 meter from the agitator assembly.
4.1.13 Add the following new paragraph:
Unless otherwise specified, agitators and auxiliaries shall be designed for unprotected outdoor
installation. Specific site climatic conditions shall be used for the agitator and auxiliaries design.

 

4.1.14 Add the following new paragraph:
Pressure containing components and mounting flanges shall be designed for pressure and
temperature of the mixing vessel. Flange rating, facing, and finish, shall be specified.
4.1.15 Add the following new paragraph:
For continuous service applications, the agitator and auxiliaries shall be designed for at least
24,000 hours of uninterrupted service.
4.1.16 Add the following new paragraph:
All welding of pressure containing parts and weld repairs shall be performed by qualified welders
and procedures qualified in accordance with ASME Section IX (2.2.1).
4.1.17 Add the following new paragraph:
Unless otherwise specified, driver, transmissions and auxiliary systems shall be furnished by the
vendor.
4.1.18 Add the following new paragraph:
Vendor shall conform to the Data Sheets for hydraulic and mechanical performance of the agitator.
4.2 Materials
4.2.4 Add the following new paragraph:
Pressure casings shall be of carbon or alloy steel for flammable or toxic services.
4.3 Agitation Assemblies
4.3.1 Add the following sentence:
Shaft shall also transmit the maximum torques at any specified operating condition.
4.3.2 Add the following new paragraph:
Split shaft designs with rigid couplings in contact with process fluid are not preferred and shall
require SABIC approval.
4.3.4 Modify second sentence as follows:
This analysis shall verify that any lateral critical speed is separated from any operating speed by at
least 40% and any torsional critical speed is separated from any operating speed by at least 20%.
4.4 Steady Bearing
4.4.2.a Add the following sentence:
The evaluation shall include details of lubrication in case process liquid is not clean or has poor
lubricating properties.
4.5 Shaft Sealing System
4.5.1 Delete ‘When specified’.
4.5.4 Modify first sentence as follows:
The shaft sealing system shall be designed so that it can be replaced without dismantling bearing
end of the agitator and shall have the following features:
4.5.4.l Add the following new paragraph:
Stuffing box shall be jacketed for heating/cooling of the sealing area, if required for the application.

 

4.5.7 Add the following new paragraph:
A throttle-bushing of non-sparking material shall be provided for all mechanical seals.
4.5.8 Add the following new paragraph:
Mechanical seal parts shall be inert to the fluids being mixed.
4.5.9 Add the following new paragraph:
For sealing systems with gland packing, the lantern and the gland shall be of split design and shall
use minimum 5 rings of packing of minimum 10 mm square section. The shaft/sleeve surface
under the packing shall be hardened to 55 HRC.
4.5.10 Add the following new paragraph:
Drains shall be provided to remove any leakage from the stuffing box.
4.7 Shaft Couplings and Guards
4.7.1 Add the following sentence:
Couplings shall be of forged steel.
4.7.8 Add the following sentence:
Coupling guard shall be fabricated from corrosion-resistant material.
4.8 Gear Reducer
4.8.3 Gear Reducer Housing
4.8.3.2 Add the following paragraph:
The gear reducer housing shall be provided with oil fill and drain features that allows maintenance
without disassembly of any component.
4.8.3.6 Add the following new paragraph:
The gear reducer housing shall be provided with a weather proof breather cap.
4.9 Drive Motor
4.9.1 Add the following sentence:
Drive motor shall conform to electrical area classification as noted on the Data Sheet.
4.9.9 Add the following new paragraph:
Electric motors shall conform to SES E06-S01 or E06-S02 and the Data Sheets furnished with the
standards.

Section 6 – Testing
6.1 Add the following new paragraph:
All tests, whether witnessed or not, shall be certified by the vendor.
6.1.7 Add the following new paragraph:
Acceptance of shop tests shall not constitute a waiver of requirements to meet field tests under
specified operating conditions, nor does it relieve vendor from responsibility in any way
whatsoever.
6.3 Optional Tests
Add the following sentence:
Requirements for optional tests shall be as specified on the Data Sheets.

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