Pressure / Vacuum Variator - 971A3
This can produce -10 PSIG to 30 PSIG (-.69 to 2.0 Bar) or 12” to 20” Hg (300 to 500mm Hg) vacuum. Max. Pressure is 20 PSIG (1.3 Bar) when used with other pressure sources. A table stand is available for bench top usage. Connections are ¼” FNPT.

Hand Pumps - B34686 (pressure); B34700 (vacuum)
These are available in 2 models, Pressure or Vacuum. The pressure pump generates a positive pressure up to 145 PSIG, while the vacuum pump generates a vacuum of 650mm Hg. Both units feature a needle bleed valve and a multi-turn vernier, which provides precise adjustment. Connections are 1/8” FNPT.

Line Traps - 932 Series
Line Traps are an inexpensive means to keep manometers and indicating fluids clean and are recommended for all installations. When installed in the line ahead of the manometer they permit entrained solids to settle out before they reach the manometer. When used with gases or vapors they trap moisture.

Sight Feed Bubblers - 931 Series
Bubblers provide a visual indication of flow by showing air or gas bubbles discharging from a dip tube immersed in a liquid in a transparent bowl. The bubble rate is controlled by a stainless steel needle valve in the head casting.
Bubblers and Line Traps are available with heavy wall transparent bowls made of either plastic or glass. They are rated at 100 PSI and 50 PSI respectively. Either a ring type or strap type configuration is available for securing the bowl to the head.

Float Check Valve - 942K50 (standard); 942KW50 (indicating fluid under water)
This is a most valuable accessory small enough to be installed on each tube of a multiple tube manometer, yet fully dependable. Normal operation of the manometer is not impaired by vertical installation of the float check valve. If pressure increases beyond the instrument range, the valve closes preventing the fluid from leaving the manometer. The valve opens when normal pressure is restored. Maximum operating pressure is 500 PSIG.

Return Wells - 934H50
These are stainless steel and for use on manometers with operating pressures up to 500 PSIG. The indicating fluid is trapped during manometer over pressure. Fluid will drain back into the manometer when normal pressure is returned.

Seal Pots - 953AA75
Meriam Seal Pots are used to provide a constant liquid head on each side of a flow meter involving steam or other condensable vapors. They also isolate the instrument from the process with a sealing liquid. All Meriam Seal Pots are fabricated from grade A seamless steel pipe. Each unit is cold hydraulic tested to over twice its rated working pressure. All connections are ½” NPT furnished with solid steel plugs. The finish is red oxide primer.

Fluids
Meriam indicating fluids are available for a wide variety of needs. Low freeze point fluids are available for cold  weather climates and outdoor use. High temperature fluids are also available for higher temperature environments.
Indicating fluid specific gravity (density) options range from 0.827 Red Oil to 2.95 Red Fluid. The higher specific gravity fluids can be used to increase the measurement range of any glass tube manometer.


Ordering Information
To order any one of Meriam’s indicating fluids, please contact your Meriam sales representative with the fluid’s  corresponding order number (see chart above