Working for a larger company at the moment, I've had the opportunity to work with a number of Z-boom pumps of different sizes and different brands. I have never had any trouble priming them in Z configuration but I prime a little bit faster than I normally would with a roll and fold. That being said, on the larger machines, I don't push my luck. I prime up in roll and fold and then configure into the Z position. It would also depend on the mix as I'm sure you understand the science behind priming a pump and how priming in a Z configuration goes against normal theory about concrete pumping we have believed to be true in the past.
As far as cleaning out is concerned, again, it probably depends on the machine. I've been on machines where they don't want to suck back in Z and machines that suck back with no dramas what so ever. I'm sure cleanliness of pipes and airtight ness of your system plays a role as well but do whatever works for you. To be more efficient as far as time is concerned on the Z-folds that don't suck back very easily, I will usually put my sponge in, proceed to start folding up until my boom sections are horizontal or until the boom is positioned so gravity is working in your favor and proceed to fold up the boom while you are sucking back.
Ok.. Here is the sience:
The reason why we have always put the boom in A frame is this: You start pumping through the pipes standing up, water ahead of the concrete.. A thin layer of slurry will hang in the pipes so the first lets say bucket of concrete will loose a lot of slurry which leaves rock and water.. No problem when pipes are standing up in an angle.. the rocks will kind of role ahead of the concrete.. Once you get it over the top the rock and water will just fall down the pipes standing down so no plug.
In Z these rocks and water will come to a stand still in the botom of the 2nd section. Rocks and water is not pumpable so this can cause a rock plugg when the rest of the concrete comes after and starts to push.
Maybe you get lucky 199 out of 200 times but one day you will get a bit shity mix and it will bite you in the ass.. You want that? Or do you play safe?
Do it the way you want but if it was my building site and a pumper would plug trying to prime in Z I would defenately not pay for the hours and mixer trucks waiting etc..
I prime out in A or Z in my opinion it should be an open Z I haven't had the balls to try a tight Z yet. I'll suck back in A or Z aswell when sucking back in the Z the sponge will only suck back when the boom lays down in the cradle in my expieriance anyway, I usually suck back a little past 2 on the vol. I've never had a problem priming out when I suck back in the Z it never leaves anything behind. To each his own though.
I have noticed that these times I plug the boom on prime (maybe once every 2 years) I can always blame it on myself.. If you follow the basic rules to the bone you should be good.
Once I primed in Z and plugged.
Twice I had 1-2-3 horizontal and 4 slightly down..
Once I stoped and closed the aircuf to early.. Mannaged to stop all the rock and water on top of the aircuff which caused a rock plug in the last 2 bends..
Once I got a hopper full of rock and still tried to prime instead just dumping the sh*t..
Etc.. All these situations could have been avoided if I would have sticked to the things I learned over the years..
I've been able to prime the 32ZZ Alliance that we have in all sorts of Z Boom configs and only ever been bit in the ass a couple time due to excessively rocky mix from the same supplier we consistantly have mix issues with. I hear Slick pack works well. Haven't tired it. This particular pump is nice for pulling a sponge back to. I just pump out, fold up and set boom in cradle and put sponge in and go. As for bigger booms. I'll always A frame as best as I can for priming and suckin a sponge.
To support our customers in the safe operation of concrete pumps, SCHWING America is providing seminars for Structural and Operation inspections. These inspections should be carried out in accordance with the inspection intervals listed below.
The seminar is designed specifically for persons who will provide structural and operational inspections for the safe operating condition of concrete boom pumps. Training materials are based off SCHWING America Inc.'s standards and procedures.
These seminars include topics which are difficult or impossible to learn on the job. Training incorporates both theoretical and practical instruction using a variety of audio-visual aids, demonstrations/techniques, class discussion, and hands-on exercises.
If you are looking for more details, kindly visit Jida Heavy Industry.
This training is intended to improve equipment condition and standards in the industry. Participating students will receive detailed instruction concerning their duties, personal responsibilities, and authority within appropriate legislation.
Students are expected to participate in all course activities, obtain 100% course attendance and a minimum course mark of 75% in order to attain successful completion.
When you submit your application along with payment, SCHWING America will make your hotel reservation for you. We will automatically reserve a room at our designated location for arriving the Sunday before the seminar and departing on Saturday morning. If you need more nights or are sharing a room with another student, please indicate on application.
In order to attend the class, students must meet the minimum requirements:
Operational Experience
Students must be familiar with and be able to proper set up a placing boom and outriggers.
Good Eye Sight
The Inspection procedure requires the inspector to make visual inspections to determine small defects such as cracks in welding.
Make inspections in very confined areas of the machine which are difficult to access.
Work often by artificial light and use a magnifying glass.
Good Physical Condition
Boom inspections require the physical ability to climb and safely hold on to overhead portions of the machine.
Inspections require the inspector to crawl under the equipment.
Inspections also require the ability to get into very tight quarters to properly inspect critical areas of the machine.
Working in confined spaces requires the ability to remain for extended periods without suffering undue discomfort or claustrophobia.
Manual Dexterity
The boom inspector must have the manual dexterity to handle and use all sorts of small and large tools and various instruments
Proper Equipment (Structural Class Only)
Students must provide their own MT and UT testing equipment.
We will process your application and send you a seminar confirmation along with lodging information and maps from the airport to the hotel and SCHWING facility. (NOTE: We will make the hotel reservation for you. All students stay at our designated hotel. Rates per evening are approximately $80.00 plus tax.)
Fly into Minneapolis-St.Paul International Airport. Attendees should plan to arrive the Sunday prior to their class and depart the following Saturday. It is the attendees’ responsibility to get to and from the airport. Cab fare from the airport to the hotel is approximately $50.00.
If you have any questions - Please call Zach Wisen 651-202-.
To complete a full boom inspection, both the structural and operational seminars must be completed.
For more information, please visit Placing Booms.