Horisontal vs vertical in-line ANSI Pump

Please advise for the following:
1. what subject I must consider before I make a decision to choose horisontal type or vertical in-line centrifugal ANSI pump for certain application.
2. Is it true that vertical pump is best for low flow and high head application?

Thank you.

 

[tstead]

Space constraints are more the issue when dealing with horizontal vs. vertical. Both types of pumps use an impeller inside a casing and work on the same principle of physics - therefore, one will not give you any inherent flow benefits over the other. While it is true that many multistage pumps are vertical (good low flow/high head conditions) there are also many horizontal multistage pumps.

Clear as mud now?

Tim

 

[butelja]

For a single stage ANSI B73.1 pump, the hydraulics will be identical as Tim has stated. Vertical pumps will have a lower installed cost because of the lesser foundation requirements, and they take up a lot less space. However, from a reliability standpoint, the vertical pumps tend to have higher vibration levels and more seal problems (unless using an expensive double mechanical seal). Beware that vertical pumps are available either with a rigid coupling and no bearings, so that the impeller is cantilevered off the motor shaft, or with a normal power frame and flexible coupling between motor and pump. The bearingless type with rigid coupling is cheaper, but far inferior in vibration levels and seal life. Either type of vertical is hard on seals because of the tendancy for the seal to run in a vapor pocket rather than liquid flooded.

If its not already obvious, I don't like vertical pumps. From a reliability standpoint, assuming all 3 are installed properly, my preferences would be, in descending order:
1.) Horizontal ANSI
2.) Vertical ANSI w/bearings and flex. coupling
3.) Vertical ANSI w/o bearings and rigid coupling - NOT RECOMMENDED

 

[MJCronin]

To all,

Butelija is right..... because of maintenance preferences and thepreference for a "good robust installation" the horizontal ANSI B73.1 pumps outsell the vertical by at least 5 to 1.

Don't forget, if the vertical ANSI pump is not properly supported (and many are not) it turns into a maintenance headache. Vibration problems can be transmitted through the attched piping. I have seen vertical ANSI pumps supported only by the conneected piping. Horizontal, baseplate mounteded pumps win hands down.

I have only seen ANSI verticals used where there is a space problem or where the fluid has a high vapor pressure. I have also seen themapplied where a small "booster" pump is needed for more head. Because of the competitive price and the availabilty of parts, many process chemical companies have a policy that says "use ANSI B73.1 hrizontal pumps, unless there is a verified, solid reason not to..."

Anyone else out there in cyberspace have musings or opinions on this ??

DEAN pump is one vendor that I can think of

Cheers....


MJC

 

[gunnarhole]

Hery,

I think the posts above cover your first question pretty well. As to your question regarding high head/low flow pumps I imagine that someone familiar with Sundyne pumps has started that rumour. They are excellent pumps in their place but they don't have much in common with an ANSI B73.2 pump.

Regards,

Gunnar

 

[BillBirch]

Another concern about vertical pumps when hot fluids are being pumped. The warm air rising from the pump casing detracts from the cooling to the electric motor.