Gaskets; Figure 2-5. Bolt Tightening Sequence - ABB MINI-MAG 10D1475 Instruction Manual

10D1475 MINI-MAG MAGNETIC FLOWMETER INSTRUCTION BULLETIN
For 4-bolt and 8-bolt flanges, tighten the flange bolts in a "star" pattern as shown in Figure 2-5 to
avoid localized stresses on the gaskets. The bolts and nuts should be tightened approximately 50%
during the first pass, approximately 80% during the second pass and to full tightness during the third
pass.

FIGURE 2-5. BOLT TIGHTENING SEQUENCE

NOTE
All 1/10 - 1/2 inch (3 - 15 mm) size Magnetic Flowmeters are supplied
for use with 1/2 inch (15 mm) pipe flange.

2.3.4 Gaskets

Use only the gaskets supplied with the instrument. The gaskets supplied with the meter are the
proper size for the meter size and type specified. When installing the meter it is important that the
correct size gaskets be utilized. Use of the wrong size gaskets could allow the inner diameter of the
gasket to protrude into the flow stream, thereby altering the flow profile within the meter. This
condition could affect meter accuracy significantly and must be avoided. Using the proper gaskets
and installing them correctly will also avoid any possibility of leakage. Observe parts information
given in Section 6.0.
CAUTION
Do not use graphite gaskets.
Under certain conditions they may cause an electrically conductive layer to form on the
inside wall of the meter, causing meter operation to degrade.
INSTALLATION 2-7