The T7 double pumps are six two-section builds that share one mounting and shaft system: T7BB, T7DB, T7DD, T7EB, T7ED and T7EE. Each letter says which cartridge group the section reads from, so the model number tells you the capacity range of both sections before you look up a single code.
Every one of the six exists in two versions. The plain model carries an ISO 3019-2 mounting flange; the same model with an S added carries a SAE J744 flange. That one letter changes the flange, the shaft codes and the port threads, which is why the S is the first thing to settle when a pump is being replaced.
Six models, two flange families
The table pairs each model with its flange and its two cartridge groups. The first letter is the front section, the second is the rear section: E is the largest group, B the smallest.
| Model | Sections | ISO version flange | SAE version flange | Weight |
|---|---|---|---|---|
| T7BB / T7BBS | B + B | 100 A2 HW, 2 bolts | SAE B, 2 bolts | 32.6 kg |
| T7DB / T7DBS | D + B | 125 A2 HW, 2 bolts | SAE C, 2 bolts | 38.6 kg |
| T7DD / T7DDS | D + D | 125-A2-HW or 125-B4-HW, 6 bolts | SAE C, 6 bolts | 56 kg |
| T7EB / T7EBS | E + B | 125 A2 HW, 2 bolts | SAE C, 2 bolts | 55.0 kg |
| T7ED / T7EDS | E + D | 125 A2 HW, 2 bolts | SAE C, 2 bolts | 66.0 kg |
| T7EE / T7EES | E + E | 250 B4 HW, 4 bolts | SAE E, 4 bolts | 95.0 kg |
The string, field by field
A T7 double is written in eleven fields, and the T7EE adds a twelfth for the coupling adaptor. The example below is the T7DD string: T7DD or T7DDS - B42 - B22 - 1 R 00 - A 1 M0 - ..
| Field | Function | Example | Values |
|---|---|---|---|
| 1 | Series and flange | T7DD |
Six models; S added for the SAE flange version |
| 2 | Front cartridge P1 | B42 |
From the group named by the first letter |
| 3 | Rear cartridge P2 | B22 |
From the group named by the second letter |
| 4 | Shaft | 1 |
One code on ISO versions, a set of codes on SAE versions |
| 5 | Rotation, seen from the shaft end | R |
R clockwise, L counter-clockwise |
| 6 | Porting combination | 00 |
00 is standard; thirty-two arrangements are diagrammed |
| 7 | Design letter | A |
Fixed for these six models |
| 8 | Seal class | 1 |
1, 4 or 5, with different pressure limits |
| 9 | Coupling adaptor, T7EE and T7EES only | not present | 0, 2 or 3 |
| 10 | Port form and thread | M0 |
Port sizes fixed per model; metric or UNC codes |
| 11 | Modification | .. |
Left blank on standard builds |
Which cartridge list each model reads from
Two of the six take both sections from one shared list, and four mix two groups. The group letters are the same as the single pump family, so a code means the same displacement whichever position it occupies within its group.
| Model | P1 front section | P2 rear section |
|---|---|---|
| T7BB | B group, shared with P2 | B group, shared with P1 |
| T7DB | D group, twelve codes | B group, thirteen codes |
| T7DD | D group, shared with P2 | D group, shared with P1 |
| T7EB | E group, ten codes | B group, thirteen codes |
| T7ED | E group, ten codes | D group, twelve codes |
| T7EE | E group, shared with P2 | E group, shared with P1 |
The three cartridge lists
Capacities are volumetric displacements in ml/rev. The B group is the smallest of the three and the E group the largest.
| B group code | ml/rev | B group code | ml/rev | D group code | ml/rev | E group code | ml/rev |
|---|---|---|---|---|---|---|---|
| B02 | 5.8 | B14 | 44.0 | 042 | 132.3 | ||
| B03 | 9.8 | B17 | 55.0 | 045 | 142.4 | ||
| B04 | 12.8 | B20 | 66.0 | 050 | 158.5 | ||
| B05 | 15.9 | B22 | 70.3 | 052 | 164.8 | ||
| B06 | 19.8 | B24 | 81.1 | 054 | 171.0 | ||
| B07 | 22.5 | B28 | 90.0 | 057 | 183.3 | ||
| B08 | 24.9 | B31 | 99.2 | 062 | 196.7 | ||
| B09 | 28.0 | B35 | 113.4 | 066 | 213.3 | ||
| B10 | 31.8 | B38 | 120.6 | 072 | 227.1 | ||
| B11 | 35.0 | B42 | 137.5 | 085 | 268.7 | ||
| B12 | 41.0 | B45 | 145.7 | ||||
| B14 | 45.0 | B50 | 158.0 | ||||
| B15 | 50.0 |
The larger cartridge goes at the front
The rule for the two positions is fixed: the larger cartridge is always fitted at the front. In the string, P1 must be equal to or larger than P2. A pair written the other way round describes a pump that does not exist, and on the mixed models it is easy to make that mistake, because the two sections read from different lists.
The shaft codes: one code on ISO, a set on SAE
This is where the S matters most. Each ISO version is built with a single shaft: code 5 on five of the six models, a keyed shaft to ISO R775 or ISO 3019-2, and code 2 on the T7EE, which is keyed to ISO 3019-2 G45N. There is no choice to make.
The SAE versions carry a set of four or five codes, covering keyed and splined shafts in SAE sizes. On the T7EES, for example, 3 is a splined SAE CC shaft with seventeen teeth, 4 a splined SAE D and E shaft with thirteen teeth, and 5 a keyed SAE D and E shaft. A shaft code from one version means nothing on the other.
Shaft torque limits
The rating is quoted as a product, Vi x p max, so a large cartridge pair reaches the limit at a lower pressure than a small one. The value is given per shaft code, and the two largest models are limited by the coupling when a second pump is driven from the rear.
| Model | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| T7BB / T7BBS | 14300 | 21420 | 20600 | 32670 | 25300 |
| T7DB / T7DBS | 43240 | 34590 | 61200 | 61200 | 42500 |
| T7DD / T7DDS | 43240 | 71750 | 61200 | 35880 | 45200 |
| T7EB / T7EBS | 68500 | 34590 | 61200 | 68500 | 68500 |
| T7ED / T7EDS | 72300 | 34590 | 61200 | 68500 | 68500 |
| T7EE / T7EES | 90380 | 114600 | 126800 | 126800 | 118340 |
On the T7EE and T7EES the rear coupling has its own limits: 20600 for an SAE B coupling and 32670 for an SAE BB coupling.
Rotation and the porting combination
Rotation is stated as seen from the shaft end, R clockwise and L counter-clockwise. The porting combination sets how the ports of the two sections sit relative to each other and to the mounting face; 00 is standard and thirty-two arrangements are diagrammed in all.
Design letter and seal class
The design letter is A across the six models. Three seal classes are offered, and their pressure limits are not the same on every page: class 1, S1 in BUNA N, is rated to 0.7 bar throughout, while classes 4, S4 in EPDM, and 5, S5 in VITON, are rated to 0.7 bar on the T7BB and to 7 bar on the other five models.
The coupling adaptor field
The T7EE and T7EES add one field in front of the port form, because a coupling can be fitted to drive a further pump. 0 means no coupling, 2 an SAE B coupling with thirteen teeth at a 16/32 pitch, and 3 an SAE BB coupling with fifteen teeth at the same pitch.
Port forms, model by model
Port sizes are fixed by the model, and only the thread code changes with the version. The metric codes are M0 and M1, the UNC codes 00 and 01, with M0 and 00 marking the larger rear port of the pair.
| Model | P1 | P2 | Suction | Metric code | UNC code |
|---|---|---|---|---|---|
| T7BB / T7BBS | 1 in or 3/4 in | 3/4 in | 2.1/2 in | M0 / M1 | 00 / 01 |
| T7DB / T7DBS | 1.1/4 in | 1 in or 3/4 in | 3 in | M0 / M1 | 00 / 01 |
| T7DD / T7DDS | 1.1/4 in | 1.1/4 in | 4 in | M0 | 00 |
| T7EB / T7EBS | 1.1/2 in | 3/4 in | 3.1/2 in | M1 | 01 |
| T7ED / T7EDS | 1.1/2 in | 1.1/4 in | 4 in | M0 | 00 |
| T7EE / T7EES | 1.1/2 in | 1.1/2 in | 4 in | M0 | 00 |
Pressure limits inside the cartridge lists
Five codes carry a lower internal pressure limit than the rest of their group, and they are the ones most often mistaken for full-range cartridges: B11, B12 and B14 are rated to 300 bar, B15 to 280 bar, B45 to 240 bar, B50 to 210 bar and 085 to 90 bar.
A second limit applies to any worn pump: once internal leakage exceeds 50% of theoretical flow, the pump must not be run for more than 5 seconds at any speed or viscosity.
Axial load and mounting torques
The axial load a shaft will carry is fixed per model, and the mounting torques differ between the two flange circles on most of the six.
| Model | Max. axial load | Mounting torques |
|---|---|---|
| T7BB / T7BBS | 800 N | 187 Nm and 61 Nm |
| T7DB / T7DBS | 1200 N | 68 Nm and 187 Nm |
| T7DD / T7DDS | 1200 N | 190 Nm and 190 Nm |
| T7EB / T7EBS | 2000 N | 187 Nm and 68 Nm |
| T7ED / T7EDS | 2000 N | 187 Nm and 187 Nm |
| T7EE / T7EES | 2000 N | 300 Nm, 88 Nm and 300 Nm |
What to confirm before ordering
- ISO or SAE. The S decides the flange, the shaft codes and the port threads, so it is settled before anything else.
- The two cartridge codes, larger one first. On the mixed models the two sections read from different lists.
- The shaft code, read against the right version. The ISO versions have one shaft; the SAE versions have a set.
- The axial load and the torque limit for the build, including the coupling limit where a further pump is driven.
Ordering
Send the complete string from the nameplate, with the S if the pump carries it. Where the plate is worn, photographs of the mounting flange and of the shaft end identify the version before anything is shipped.
The six models are listed here: T7BB and T7BBS double pumps · T7DB and T7DBS double pumps · T7DD and T7DDS double pumps · T7EB and T7EBS double pumps · T7ED and T7EDS double pumps · T7EE and T7EES double pumps. Cartridge kits for the E and B sections are in the front kit listing, the full range is on the T7 double pump page, and the T-series overview covers the rest of the family. Specific strings can go through the contact page.
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