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Viewing inquiries for 07-317504

Inquiry #1: Spec is written by Flygt. This is clearly not a competitive bid. Comments below will address concerns with sole-source language along with general design issues. The 'or equal' is impossible to meet; unless the spec is revised, any mfr not named Flygt will be taking significant exceptions.

#1
74-2.02B(1)(d) Closed loop cooling system

Drawings show new pumps will be installed in a wet-well. Float liquid levels are not shown. What is the purpose of the cooling system? If there is no liquid in the sump, the pump will not run. The intent of cooling system is to protect motor in a dry-pit installation. In a wet-pit installation, it offers no benefits and exists only to increase pump cost and delivery.

Pump schedule shows some pumps as wet-pit, some as dry-pit. Are the wet-pit pumps excluded from the cooling system?

#2
74-2.02B(1)(e) Cable entry

Epoxy sealing not allowed. This is language used by Flygt with the intention to eliminate mfrs that use an epoxy system. ABS cable entry is similar to Flygt. Fairbanks, Grundfos and KSB use epoxy. Fairbanks is named --- yet they can't use their epoxy system?

#3
74-2.02B(1)(f) Motor

Minimum 30 starts per hour. This needs to be revisited. Generally, 15 to 20 starts per hour is the upper limit. Has Caltrans confirmed with a mfr other than Flygt that 30 starts per hour is achievable? Is this realistically what the pumps will see during normal operation?

#4
74-2.02B(1)(g) Shielded Power Cable

This is a significant modification to the cable system. Mfr engineering staff would need time to review these modifications and determine how to incorporate them. It would be a significant price adder. Please clarify the purpose of requiring the shielded cable.

#5
74-2.02B(1)(i) Mechanical Seals

Flygt uses tungsten carbide. ABS, KSB, and Grundfos use silicon carbide. Fairbanks depending on the pump size uses either silicon or tungsten or a combination. Not really necessary to make a change to the spec if you will consider either material in submittal phase.

#6
74-2.02B(1)(k) Impeller

This is a definitive example of sole-source Flygt language. Why is a chrome cast iron impeller being requested on stormwater? Flygt manufacturing over the years has purposely pushed this material as a way of ruling out submersible mfrs who don't offer this material. It also drives up the costs unnecessarily.

All submersible manufacturers can point to installations where a cast iron impeller was used on sewage for 10+ years without repair or service. Agencies like City of LA and LACSD have put out specifications in the past several years for heavy-duty sewage submersible pumps, none of which have required chrome iron impellers. We are not pumping sewage here --- we are pumping stormwater. So even less of a reason to use chrome cast iron.

Additionally, a semi-open impeller does not have a shroud on the suction side and rotates against an adjustable suction wear plate, which results in a high amount of wear on the impeller. Semi-open impellers rely on a sharp leading edge to cut material in the wastewater, which allows them to remain clean and help prevent clogging; therefore a hard iron / chromium / nickel alloy is required to keep the semi-open impellerâ€™s leading edge sharp.

The clearance between the semi-open impeller and the adjustable suction wear plate plays a critical role in helping to avoid clogging. There is always the possibility of fibrous material in the raw sewage getting caught between the semi-open impeller and the adjustable suction wear plate if that gap opens; therefore the gap in the semi-open design must be checked and periodically adjusted, which is a maintenance action that is often overlooked. The spec even states the clearance shall be adjustable.

You would be better off allowing a double-shrouded design with mandatory replaceable wear rings to protect a cast iron impeller. The wear rings can be made from harder metals like stainless steel and do not need adjustment to maintain close tolerances.

#7
74-2.02B(1)(l) Volute / Suction Cover

This language is tied into the chrome cast iron impeller and gives Flygt a clear competitive advantage over other mfrs.

#8
74-2.02B(1)(m) Protection

The Fourth Street OC station pumps are too small to incorporate the float switch leakage chamber.

The spec asks for the MiniCAS control unit. MiniCAS is a Flygt trademark, i.e. sole-source language intended to rule out other mfrs. This is not competitive bidding. Each mfr should be able to offer their control unit designed to work with their pump. Asking a non-Flygt mfr to tinker with electronics to fit the MiniCAS is unreasonable.

#9
Named Mfrs

Flygt, Fairbanks, Barnes, or equal. Barnes doesn't even make pumps of this size. Fairbanks will take exception to the cable entry, volute design, and impeller design. So basically, Flygt sole-source but other mfrs thrown in along with 'or equal' to give the appearance of a competitive bid. Not acceptable for a Caltrans project.

#10
Pump Drawings

Drawings show pump mounted on a stand that is bolted down to the sump floor. Submersible mfrs make either a wet-well pump that rests on the discharge piping and is raised/lowered using a guide rail system, a dry-pit pump that utilizes a suction elbow, or a wet-pit portable pump that sits on the sump floor and is not bolted down.

The design indicates a wet-pit pump with a special stand that bolts down. We are certain Flygt already has provisions for this stand, given the rest of the spec is geared toward them. All other mfrs are now under a time constraint to design such a stand and ensure it adheres to their engineering requirements.

This stand adds to the confusion of why dry-pit motors are being requested, and whether these pumps have guide rail systems. Clarifications are needed on why this stand is requested and whether guide rail system is needed.

#11
Warranty

Not mentioned in the spec. What is the pump warranty requirement?

#12
Spare Parts

Not mentioned in the spec. Are spares parts to be supplied?

#13
Motor HP Requirements

Drawings state motor HP for each station, but the HP given is at the duty condition. HI dictates sizing for end of curve. For example, Eastern Ave states 85HP, but when sizing per HI, a 100HP motor is needed. This can vary from mfr to mfr, but Caltrans can expect that the actual motor HP for each station will not necessarily correlate to the drawings. Has this been discussed or reviewed? Will existing electrical support higher HPs if dictated by HI requirements?
Inquiry submitted 10/31/2019

Response #1:1) Cooling system is not needed if submitted pump with motor will not be running at a water elevation with motor exposed to air for a period not recommended by the manufacturer. 2) Cable entry can be epoxy sealed. 3)20 starts per hour will be acceptable. 4)Shielded cable is only required for VFD powered pumps. 5) Silicon carbide and tungsten carbide are both acceptable. 6)Double-shrouded design with mandatory replaceable wear rings with cast iron impeller is also acceptable. 7)Double-shrouded design with mandatory replaceable wear rings with cast iron impeller is also acceptable. 8)No leakage chamber required on 4th st pumps. Control unit must be compatible with all submitted pump and MCC’s and with language of the electrical specifications. 9)See above comments. 10)All of the pump stations will be wet pit installations, some are existing wet pits, some are existing dry pits that will be converted to wet pits. No guide rail mounted pumps will be accepted. All pumps must be stand mounted and secured to the floor of the pump station as shown. 11) See section 5-1.47 GUARANTEE of the 2018 Caltrans standard specifications. 12)Attach typical spare parts list if any manufacturer normally provides as part of the pump submittal for review. 13) Since Caltrans can’t design for all possible pumps submitted. HP shown on the plans is suggested HP. Pumps submitted with larger HP will need to be reviewed on a case by case basis during the submittal process to assure they meet the electrical supply conditions.

Response posted 10/31/2019

The information provided in the responses to bidder inquiries is not a waiver of Section 2-1.07, "JOB SITE AND DOCUMENT EXAMINATION" of the Standard Specifications or any other provision of the contract, nor to excuse the contractor from full compliance with the contract. Bidders are cautioned that subsequent responses or contract addenda may change a previous response.