26-VSW-UNK-004 Amendment 2.pdf
PDF 520 KB Posted
- Solicitation number
- ITB 26-VSW-UNK-004 Unalakleet Covenant Lift Station Project
- Issued by
- Matanuska-Susitna Borough, Trapper Creek CDP, Alaska
About this file
This amendment document is issued by the State of Alaska Department of Environmental Conservation's Village Safe Water Program regarding ITB 26-VSW-UNK-004 for the Covenant Lift Station Project. The document addresses a vendor question about pump specifications for the lift station project, with responses due August 21, 2025 at 2:00 PM AST. The vendor questioned whether the specified Vaughan S3P-082 pump model could meet the required head and flow parameters, suggesting an alternative S3V model with 20HP capacity to handle the 93-106 TDH and 225.5-232.5 GPM requirements.
The department's response clarifies that the original pump specification is correct, explaining that the pump curve shown in the project drawings was based on an incorrect impeller size. Using the correct 8.20-inch impeller size, the specified Vaughan S3P-082 pump with 7.5 HP motor will achieve the desired single pump operating point of 160 gpm at 54.7 ft TDH. The amendment includes an attached pump performance datasheet confirming these specifications, showing the pump operates at 1730 rpm with 49.12% efficiency and requires a minimum 7.50 hp motor rating for water service applications.
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Other files
| File | Type | Posted |
|---|---|---|
| 26-VSW-UNK-004 Amendment 3.pdf | ||
| 26-VSW-UNK-004 Amendment 1.pdf | ||
| ITB 26-VSW-UNK-004.pdf |
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Text version
State of Alaska Department of Environmental Conservation
Village Safe Water Program 555 Cordova Street
Anchorage, AK 99501 john.mcdonald@alaska.gov
August 6, 2025
To: Vendor List
Re: Amendment 2
ITB 26-VSW-UNK-004
Covenant Lift Station Project ITB Due Date: August 21, 2025 @ 2:00 PM AST
The following are vendor questions and the department’s response:
1. Vendor: Can you please confirm with the Engineer on which pump they would like us to select for this application. Per the pump data and design criteria page a Vaughan S3P-082 was selected and listed. That Model Vaughan pump will not hit the Head and Flow listed. The HP is also incorrect for those Duty Points. We worked with the Vaughan Factory Rep and he helped us select the Vaughan S3V in 20HP which will handle both the 93-106 TDH and also the 225.5-232.5 GPM. Please pass along this info to your Engineer so they can make the change or give an explanation on why they need the S3P.
Department: The pump curve shown in Attachment 3 Covenant Lift Station – IFC Drawings (page 12, under [1] CL-001 Pump Data and Design Criteria) is based on an incorrect impeller size. Using the correct impeller size (8.20 inches) results in the desired single pump operating point of 160 gpm at 54.7 ft TDH. The specified pump (Vaughan S3P-082 with 7.5 HP motor) is correct. See attached Pump Performance Datasheet for Vaughan S3P-082.
John McDonald
Procurement Specialist
Vaughan Quotation System 23.0.2
Vaughan Company, Inc. · 364 Monte-Elma Road · Montesano , WA 98563 phone: 1-888-249-CHOP · fax: 1-360-249-6155 · Chopperpumps.com
Pump Performance Datasheet Customer :
Customer reference :
Item number : 001 Service :
Quantity : 1
Quote number : 1873094 Size : S3P - Trim Dia Stages : 1 Based on curve number : E3P-1750-TD Date last saved : 17 Apr 2023 9:00 AM
Operating Conditions Flow, rated : 160.0 USgpm Differential head / pressure, rated (requested) : 47.00 ft Differential head / pressure, rated (actual) : 54.69 ft Suction pressure, rated / max : 0.00 / 0.00 psi.g NPSH available, rated : Ample Site Supply Frequency : 60 Hz
Performance Speed criteria : Synchronous Speed, rated : 1730 rpm Impeller diameter, rated : 8.20 in Impeller diameter, maximum : 10.30 in Impeller diameter, minimum : 8.00 in Efficiency : 49.12 % NPSH required / margin required : 6.37 / 0.00 ft Ns (imp. eye flow) / Nss (imp. eye flow) : 1,190 / 3,752 US Units MCSF : 60.00 USgpm Head, maximum, rated diameter : 68.64 ft Head rise to shutoff : 25.53 % Flow, best eff. point : 225.5 USgpm Flow ratio, rated / BEP : 70.96 % Diameter ratio (rated / max) : 79.61 % Head ratio (rated dia / max dia) : 54.35 % Cq/Ch/Ce/Cn [ANSI/HI 9.6.7-2010] : 1.00 / 1.00 / 1.00 / 1.00 Selection status : Acceptable
Liquid Liquid type : Water Additional liquid description :
Solids diameter, max : 0.00 in Solids concentration, by volume : 0.00 % Temperature, max : 68.00 deg F Fluid density, rated / max : 1.000 / 1.000 SG Viscosity, rated : 1.00 cP Vapor pressure, rated : 0.34 psi.a
Material Material selected : Standard
Pressure Data Maximum working pressure : 29.71 psi.g Maximum allowable working pressure : 150.0 psi.g Maximum allowable suction pressure : 100.0 psi.g Hydrostatic test pressure : 0.00 psi.g
Driver & Power Data (@Max density) Driver sizing specification : Maximum power Margin over specification : 0.00 % Service factor : 1.00 Power, rated : 4.50 hp Power, maximum, rated diameter : 6.35 hp Minimum recommended motor rating : 7.50 hp / 5.59 kW
Flow, rated : 160.0 USgpm
Differential head / pressure, rated (actual) : 54.69 ft
Impeller diameter, rated : 8.20 in
Minimum recommended motor rating : 7.50 hp
Selection status : Acceptable
| 26-VSW-UNK-004 Amendment 2 v1 - not signed.pdf |
| S3P Pump Selection Output.pdf |
File details come from the government source that posted it. Updated .