Clear Water Catch Test - Steam LP & EP
SLAYER calculates the flowrate (water debit) of Steam Series machines by measuring the dispensed amount of water, in grams (milliliters), against time, in seconds. Measuring flowrate allows a technician to determine brew circuit health and identify if any restrictions or mechanical faults are present. Additionally, measuring flowrates without a dispersion screen & screw and while in automatic (volumetric mode) reduces human error and minimizes water retention in the brew circuit.
This guide will instruct a technician how to measure the flowrate on a Steam EP & LP (Pre-Infusion + Full Brew).
Tools:
- Scale
- Vessel
- Stubby Flathead Screwdriver
- Pen & Paper
- Calculator
SLAYER Steam LP: Full-Brew Catch Test
Objective:
Clear water catch test is designed to measure water
(grams) dispensed over a variable length of time (seconds). Since the Steam LP
measures volumetrics in grams, we will use the formula: WT/Time = Grams per
Second (G/S), to calculate our flowrate. The goal is to identify if each group
is dispensing an average amount of water relative to each other. Measured in
grams per second the variance between groups should be no greater ~2g/s.
Step 1 - Group Settings:- Enter Menu on Group 1:
- Scroll to AutoFlush and select:
- <OFF>
- Scroll to Brew Parameters and select:
- <Shot1>
Group <ALL>
- Change recipe values to:
- Pre:
0.0s
- WT:
30g
- Post:
0.0g

*It is imperative to change all values to zero except for
WT (30g) for volume accuracy.*
Step 2 - Prepare Group:

Group must be at set temperature prior to catch
test.
- With a stubby flathead screwdriver. Remove
dispersion screw and screen on both all groups.
- Place scale and vessel underneath group.
- Actuate to POS1 (verify WT stops at 30g on
display) to rinse group.
Step 3 - Clear Water Catch Test:- Once the group has been rinsed.
- Tare scale.
- Actuate to POS1 (Shot 1).
- Record weight (grams) observed on the scale.
- Record time (seconds) observed on the display.
- Tare scale.
Repeat an additional two times for a total of three clear water catch tests.
Step 4 -
Calculate Results:
- Add all three weights together.
- Add all three times together.
- Use formula: WT/Time to calculate average
flowrate.
Repeat for groups two and three.
Step 5 - Analyze Results:
After the clear water catch test has been completed for each group and flowrates have been calculated. We can determine if the flowrates are out of spec.
For the Steam LP, SLAYER expects flowrates to be within ~2g/s between each group. If any group is outside the expected parameter. Further troubleshooting by a SLAYER experienced technician will be required.
SLAYER Steam EP: Catch Test
Objective:
Clear water catch test is designed to measure water (grams) dispensed over a variable length of time (seconds). Since the Steam EP measures volumetrics in grams (adjusted by pulses in the menu), we will use the formula: WT/Time = Grams per Second (G/S), to calculate our flowrate. The goal is to identify if each group is dispensing an average amount of water relative to each other. Measured in grams per second the variance between groups should be no greater ~2g/s.
Step 1 - Group Settings:- Enter Menu:
- Scroll to Pre-Wet.
- Buttons will illuminate. Select Button 1.
- Adjust Pre-Wet and Hold to <0>
- Save to all groups.
- Re-enter menu and scroll to Brew Volume Program Dose.
- Buttons will illuminate. Select Button 1.
- Set pulse count to <300>
- Save to all groups.

*It is imperative to set Pre-Wet & Hold to <0> and pulse count to <300> for volume accuracy.*
Step 2 - Prepare Group:

Group must be at set temperature prior to catch test.
- With a stubby flathead screwdriver. Remove dispersion screw and screen on both all groups.
- Place scale and vessel underneath group.
- Press Button 1 to rinse group.
- Reminder! Setting Button 1 to <300> pulses equals approximately 30grams.
Step 3 - Clear Water Catch Test:- Once the group has been rinsed.
- Tare scale.
- Press Button 1
- Record weight (grams) observed on the scale.
- Record time (seconds) observed on the display.
- Tare scale.
Repeat an additional two times for a total of three clear water catch tests.
Step 4 - Calculate Results:
- Add all three weights together.
- Add all three times together.
- Use formula: WT/Time to calculate average flowrate.
Repeat for groups two and three.
Step 5 - Analyze Results:
After the clear water catch test has been completed for each group and flowrates have been calculated. We can determine if the flowrates are out of spec.
For the Steam EP, SLAYER expects flowrates to be within ~2g/s between each group. If any group is outside the expected parameter. Further troubleshooting by a SLAYER experienced technician will be required.
Example Catch Test:
Imagine the values below written on a note pad after collecting data from steps 3-4.
Steam LP - <30g> Brew Parameter WT yield:
Steam EP - <300> Brew Volume Program Dose yield:
- 58.7
- 60.2
- 59.1
Total:
178/3 = 59.3g
Time, measured in seconds on display:
- 7.9
- 7.8
- 8.1
Total:
23.8/3 = 7.9s
Using the formula, WT/Time = Flowrate, we determine
59.3g/7.9s equals a 7.5g/s flowrate.
Troubleshooting & Resources:
SLAYER recommends all service be performed by an experienced SLAYER Espresso trained technician. For a technician reference near you, please contact SLAYER Support at (206)-284-7171 (#1 in Directory) or email support@slayerespresso.com.