GN Shaker Screen is a subcompany of GN solids control which is API Q1 certified company.
North America Hydrovac Slurry Treating System
GN Soids Control has designed and manufactured many sets of hydrovac slurry treating systems to North America.
Here are some other questions that asked by our customers. In our system, we fixed 2.5inch opening gratings to catch rocks. Do you want to add a second grating with smaller openning？
Shaker Tank System GNXT7015-02
What is back up plan if we experience surge runoff and/or rapid frequent plugging of coarse shaker ZKR-1230 wedge wire screen panels?
One of your workers should monitor the coarse shaker when hydrovac truck dumps into the catch hopper. So if he noticed surge run off of rapid plugging, will need to decrease the feeding, use high pressure water to flush the screen panel to clean thoroughly. In fact, all the screen panels must be cleaned thoroughly every other time in case they are blocked, especially the finer shaker and desilter shaker's screen panels. 
We know of other operations mostly converting to polyurethane of coarser 3 or 4 mm opening. Do you have these? Would coarsening plug pump?
2mm is advised by our customer, we do manufacture coarser opening screens.
If changed to coarser opening, the submersible pump wears fast (such as the impeller), bearing also has a higher chance to broke when the duty increased. There is not specific data we can give due the slurry varies a lot. The good point is coarse shaker treating flow rate will be increased, while the discharged solids will be a little bit more moisture.
In addition to coarser polyurethane screen openings, spray nozzles are mounted above screen often needing supplemental hosing beyond that.
BTW, GN Solids Control just provided another 4 sets hydrovac slurry treating systems to USA customers. In order to have a larger treating flow rate, we provided a decanter centrifuge from 22inch to a 30inch centrifuge.
GN Hydrovac Treating System
GN Solids Control provided some sets of hydrovac slurry treating systems in North America. By using one set of GN hydrovac slurry treating system, it can help to treat 30~50 truckloads every day.
Today we would like to share some questions our customers have, hopefully if you have similar questions, you will also find answers in the following:
1.What do you think about us pumping clean mud through these nozzles? We are very concerned about preserving water! Can we possibly re-direct mud from GN submersible slurry pump GN50YZ40A-10 on coarse shaker tank to introduce into flush nozzles?
Suggest you pump the water discharged from GN decanter centrifuge to flush, or at least use the water from the desilter tank. Too many solids in the coarse shaker tank, might block the nozzles.
2.What is your experience with functionality of guillotine valve critical to control feed to coarse shaker? We add motor actuation to this valve.
According to our former experiences, our customers usually keep the valve in a normally open status, which is seldom adjusted. Slurry discharge is controlled by the hydrovac truck. It's good to use a motor actuation for sure, as long as the coarse shaker can treat all the feed slurry, you can leave the valve fully open. But use motor actuation is option for high configuration system.
3.What do you think about install of removal grizzly bar sets at grade above square mesh for safety/ease of picking out rocks, trash,etc..? 
In our hydrovac slurry treating system, we fixed 2.5inch opening gratings to catch rocks. Do you want to add a second grating with smaller opening？GN opening gratings also help to protect the coarse shaker.
Now all those GN hydrovac slurry treating systems running well in customers’ work site. If you are feeling headache for treating hydrovac slurry, come to GN Solids America for your customized solution.
GN Vacuum Pump In Houston
GN Solids Control just exhibited several vacuum pumps in CIPPE show, and in the coming Houston OTC show, GN Solids Control will also exhibit a vacuum pump.
GN made vacuum pump is mainly used to transfer oil sludge which has high solids content as well as large viscosity. 
GN Solids Control manufactures 3 different models vacuum pumps, include 10 m3/h, 20 m3/h and 40 m3/h. GN Solids Control manufactures different types of feeding pumps, such as screw pump, centrifugal pump, submersible pump. Most GN pumps are electrical driven or hydraulic driven, while for the vacuum pump it’s air driven. Need to use an air compressor to provide constant air, different models need different air feeding flow rate.
GN vacuum pump can work continuously, 2 control methods: manual control or automatic control. The 10 m3/h and 20 m3/h vacuum pump are both fixed with wheels for convenient move, and the 40 m3/h vacuum pump is fixed and strengthened by a frame which can be moved by forklift. The max. Size particles can be transferred by vacuum pump is 75 mm with the solids content of 80%.
GN vacuum pump suck and discharge every other seconds, in order to work continuously, several different vacuum pumps can be matched together to work as a whole unit. Last year, GN Solids Control provided 2 sets whole systems that working an offshore drilling rig sites. Each set has 4 sets vacuum pumps and all put in one 40FT size container. 
Based on the transferred material or slurry, GN Solids Control provides different pump materials, such as the contact fact of the inlet and outlet as well as the air valve are optional for SS 316, and the whole pump shell can be also made by SS 316.
Feel free to connect with us if you have some headache when trying to move some sludge, GN vacuum pump probably be your best choice.
