Need to know what the abbreviation on this drawing means.

[dgeorge]

I have a schematic for the installation of a sewer drain pipe and grinder pump that contains the abbreviation "FL" on it (I have circled it in red). Can anyone tell me what the "FL" abbreviation stands for. Thanks!

 

[Caduceus]

Appears to mean "floor level". (Got the 10 characters...whew!)

 

[havasu]

Usually FL is used to describe floor level, flood level or frost line. Other that that, it would be a guess....and since I'm on my Droid phone, I can't see the picture well. In a few, some experts will be replying to tell us both what it actually means.

 

[dgeorge]

So, assuming that means floor level, the 4" pipe leaving the house is at 2.7' below floor level and the main line in the left of the drawing is at 4.2' below floor level, that would translate to a slope of 1.5' over 58' of new line or 5/16 of an inch per linear foot. Seems to me that ought to be plenty of slope if a four inch (4") pipe was used for the whole line. In other words, why go to a 1.5 inch pipe and a grinder pump? I thought grinder pumps were used for applications where solids need to be ground and pumped the UPHILL to a main line. Am I correct in these assumptions?

Thanks!

 

[havasu]

As usual, I'm a day late and a dollar short!

 

[dgeorge]

Repost:

So, assuming that means floor level, the 4" pipe leaving the house is at 2.7' below floor level and the main line in the left of the drawing is at 4.2' below floor level, that would translate to a slope of 1.5' over 58' of new line or 5/16 of an inch per linear foot. Seems to me that ought to be plenty of slope if a four inch (4") pipe was used for the whole line. In other words, why go to a 1.5 inch pipe and a grinder pump? I thought grinder pumps were used for applications where solids need to be ground and pumped the UPHILL to a main line. Am I correct in these assumptions?

Thanks!

 

[havasu]

I believe that question should be better answered by whoever drew out the sketch. Maybe someone here might have the ability to answer you, so this post will serve as another bump to the top for you!

 

[Chris]

In my line of work it means Flow Line Which would be the bottom of the pipe. Spring line is halfway up the pipe. From that drawing it looks as if the guy who drew it meant Flow line but I could be wrong.



It looks as if you have a 6" Sewer lateral coming of a a SMH (Sewer Manhole) (most homes are 4" not 6" so I would question that). According to the plan they want you to do a 6" cut in Wye with a 6" x 4" Bushing and then a 4" x 1-1/2" Bushing and run the 1-1/2" Solvent weld pipe. Along witht he wye they are requiring a new 6" Clean out, How I read this is that the existing line is 4.2' deep to flow line (Where the tie in is being done) and the 4" Cast Iron stub out of the house is at a cut of 2.7' deep to flow line. ( if there is a pump that would mean there is reverse flow so there is a manhole of some sort with a pump in it and I would assume the outlet of that is the cut of 2.7'. From what I read you have a fall of 1.5' (18")in 58 feet of pipe so you have a fall of .31 inches per foot which is greater then 2% which is fine.

I hope this mumbo jumbo makes any sense to you.

 

[dgeorge]

In my line of work it means Flow Line Which would be the bottom of the pipe. Spring line is halfway up the pipe. From that drawing it looks as if the guy who drew it meant Flow line but I could be wrong.



It looks as if you have a 6" Sewer lateral coming of a a SMH (Sewer Manhole) (most homes are 4" not 6" so I would question that). According to the plan they want you to do a 6" cut in Wye with a 6" x 4" Bushing and then a 4" x 1-1/2" Bushing and run the 1-1/2" Solvent weld pipe. Along witht he wye they are requiring a new 6" Clean out, How I read this is that the existing line is 4.2' deep to flow line (Where the tie in is being done) and the 4" Cast Iron stub out of the house is at a cut of 2.7' deep to flow line. ( if there is a pump that would mean there is reverse flow so there is a manhole of some sort with a pump in it and I would assume the outlet of that is the cut of 2.7'. From what I read you have a fall of 1.5' (18")in 58 feet of pipe so you have a fall of .31 inches per foot which is greater then 2% which is fine.

I hope this mumbo jumbo makes any sense to you.

Thanks Chris! I understand the majority of your post. Here's what I don't get: if the cast iron pipe coming out of the house is at 2.7 ft deep to the flow line and the existing connection is at 4.2 ft deep to the flow line where it connects to the main line at the wye, then why would a pump be needed at all? Wouldn't gravity do its job in this instance?

 

[Chris]

I agree it doesn't make sense unless the home is down a slope. It all depends. For us the 4.2 could be up by a rd and the house set back down a slope that is below that 4.2 cut. How is the terrain there? If it is flat then it doesn't make much sense unless there is already a pit and this is the elevation of the outlet pipe from the pump.

 

[dgeorge]

Thanks Chris. You have answered my ultimate question. The house is not downslope of the main line. Rather, it is up slope. And, the pipe coming out of the house is definitely higher up in elevation than the main. My conclusion is that the contractor is trying to sell a product and the installation of it that is unnecessary. Thanks again to everyone for helping me understand this drawing.

 

[dgeorge]

One last question for everyone. Assuming the slope on the crawing is correct and I do NOT need a grinder pump, what should I reasonably expect to pay to have the excavation done, purchase the materials, and install solvent welded 4" pipe from the outlet to the existing wye at the main by a licensed plumber working under fully permitted conditions? Thanks!

 

[Chris]

You might want to wait for a plumber or two to answer that last question because I am an underground utility contractor and my prices tend to be slightly higher then plumbers do to all the excess insurance I am required to have. But to answer you question I would be in the few grand area assuming all work is down in the dirt are.

 

[dgeorge]

Thanks Chris. All work is below grade. The area is very rocky however.

 

[Chris]

Rocky will cost a little more depending on the contractor doing the work. Also if there is any blasting required it will be much more.