1. Filter drilling status
Claudio Bortolin
Andrea Francescon
Yannick Lesenechal
Samuel Rambaut
Rosario Turrisi

2. The picture Reminder Some pollution went into the lines
It had to go through molecular sieve/hydrofilter of the plant (2 μm filter was installed after 1 year run)
and/or
It had to go through the first 60 μm inline filter and clog (and partly go through) the second inline filter
The second clogged filter cannot be replaced (have to disassembly the experiment) and causes:
less flow
pressure drop
The liquid heats up to room temperature along the path to the detector (~40 meters) – this was not a problem, if alone
The combination of the last two causes:
less flow in the single line  worse performance in the sector
bubbling before the capillaries  local and occasional loss of performance

3. The environment Reminder Layout of the PP4-PP3 pipe Access point
(2) Target point
See next slide for a zoom-in

4. The target Reminder D X T Filter Swagelok SS-4-VCR-2-60M L S
D = mm
T = mm
X = 0.7 mm (~1 mm in the filtering area)
S = 4 mm
L = ~4500 mm D X T
Filter Swagelok SS-4-VCR-2-60M L S
Pipe: SS 316L 4-6 mm i-o diameter
Swagelok 316 SS VCR Face Seal Fitting, 1/4 in.
Female/Male Nut: SS-4-VCR-1 & SS-4-VCR-1
Swagelok gland 6LV-4-VCR-3-6MTB7
SEM picture of the filter

5. Tools Reminder Drilling: Cleaning:
tungsten carbide tip welded on twisted ss cable
drill to operate the rotation
counter-flow at 200 mbar w/manometer to detect the presence of the hole
Cleaning:
rilsan pipe connected to a rotary vane vacuum pump
magnet tip on twisted ss cable
cleaning machine to force counter-flow wise a cleaning fluid

6. Reminder Edwards RV3 rotary vane 2-stage pump magnet cleaning machine
Ø 2.5 mm ss twisted cable
tungsten carbide 5-faces tip
Ø 2.5 mm ss twisted cable

7. Procedure Reminder TESTED DRILLING > 100 FILTERS !
Pre-drilling cleaning
remove particles in the pipe
same procedure as cleaning
Drilling:
rotation of the tool inside the pipe by the drill
pressure drop (~20-30 mbar) on a manometer with specific trend when hole done
Cleaning:
suction of drilling remains with small pipe inside the stainless steel pipe (down to the filter) and vacuum pump
‘’walk’’ with magnet inside the pipe
the steel of the filter is slightly magnetic
counter-flow with C6F14 for 1.5 bar
pipe drying with Ar 1.5 bar
repeat more times (5 cycles total)
last counter-flow with fluid lasts 12 h
TESTED DRILLING > 100 FILTERS !

8. First application Flow= 2.0 g/s @ 4.75 bar Modules on= 100%
‘’Attack’’ first sector: #9
It never worked properly
First one to be turned on for some time: 12/12/2007, h 15:13, for 41’
Pre-cleaning:
4 cycles
vacuum cleaning + 3 magnet sweeps + vacuum cleaning + counterflow
last counterflow left running overnight
flow: from 0.27 to 0.46 g/s
Drilling: February 15 morning
Cleaning: 5 cycles (overnight counterflow between cycle 3 and 4)
Results:
Was: bar
Flow= bar
Modules on= 100%
Was: 0%

9. Further drilling! First intervention: success!
Also sector #7 (0% on) and #6 (42% on) are in bad shape
Drilled both (#7 on Feb 27, #6 on March 6)
Pre-cleaning done as in previous cases
Cleaning: ‘’standard’’ 5 cycles, but:
Results were not satisfactory on sector #7, cleaned for 1 more day
Results:
once again full performance recovered on both sectors!
half stave 6C0 has electronic issues – cannot be turned on

10. Sector #7 analyses - 1
First cycle of cleaning…

11. Sector #7 analyses - 2 Second cycle of cleaning… ok!
On the filter
On the carbon sticker

12. New flow conditions Old flow rate values from last November
7 sectors above nominal value
3 drilled, 4 because of pre-drilling cleaning
Sector #3 had 12 hs on, one went hot, expect still a few more
1.8 g/s
new flow rate values
old flow rate values
drilled filters

13. Current performance Most work of configuration done
T/power distributions consistent with previous, but…115 hs on!!
Were 116, one hot on sector #3, still with low flow

14. Current acceptance
Efficiency changed from this… to this! (and more to come!)
62.5% (75/120 on) - Nov, % (115/120 on) - Mar,

15. Perspectives Expect a few hs lost in next weeks
flow not ideal yet in 3 lines
Drill 1-2 sectors at next TS
3 only left with low flow: 5, 3 and 4, in descending performance order
Late delivery of the fiberscope, images of the drilled filters can be done at next TS

16. Let’em flow!
Lake Barriessa, Napa County, California, US