VAV H2S Media Change Out Procedure

Rev Log: Date and Description

• 10/16/20 - Initial Document Creation

• 4/9/221 - PPE update

Pressure Differential Gauge (PDG) – Measures the pressure difference between one side of the VAV and the other

H2S Vessel - These are the vessels that provide final H2S pretreatment of RAW Biogas coming from digesters

LOTO – Lockout Tagout

SOP – Standard Operating Procedure

PPE to be worn

• Safety Shoes

• 4 Gas Monitor (Preferred) or H2S Monitor (minimum)

• Safety Glasses

• N100 Mask

• Laytex or Nitrile gloves

• Long Sleeve Shirt

Equipment needed for procedure

• 1- 32mm, 2" sockets and ½” Impact

• 1- 32 closed end wrench

• 1 - 2" closed end wrench

• 1 - > 500 ft-lb torque wrench or torque multiplier

• Lull preferably 12K and one with tilting head. This makes dumping media in vessel easier

• 1 - Lifting Strap

Parts required

SOP-UTM-01X LOTO SOP

SOP-UTM-01X Working from height SOP

QWI–UTM–33X Pressure Removal Work Instruction

QWI-UTM-00X Leak Test Work Instruction

Remove Pressure from the H2S Vessel

• Once the pressure is removed Lockout the feed compressor motor and the feed compressor local control panel.

• Follow LOTO procedure

• Isolate suspect vessel by closing both inlet and outlet valves

• Open small ball valve on Inlet end of vessel and leave open during duration of maintenance.

Media disposal

• Vessel is picked up by waste removal company and dumped off site at their facility

• Vessel is returned clean by waste removal company

• Reattach all HDPE piping

• Reattach Grounding cable on front and rear of VAV

• Verify rear door is sealed properly and gasket is serviceable

Replacing the media

• Use Telehandler and supersack lifting accessory to lift media above manway

• Loosen and remove the bolts that hold the hatch in place

• Check gasket for cleanliness and dry rotting

Adding new H2S media

• Orient lull so open end of media can be placed over vessel opening and begin lifting media up to vessel.

• Once media is in place, open bag of media utilizing dump tube and begin dumping into vessel. You will have to repeat the previous 3 steps 3 times in order to adequately fill the vessel.

• Replace hatch cover and locking bolts

Preparing for re-start

• Verify that all material is removed from the skid area

• Verify that all tools are removed and accounted for

• Verify that no personnel are able to be injured as result of the start-up

• Remove the LOTO to the Feed Compressor VFD and localized electrical control panel.

Re-pressurizing the system

• See the QWI-UTM-33X Re-Pressurizing Work Instruction for Pressurizing the gas train.

Perform Leak Test to all fittings and covers removed

• Follow QWI-UTM-00X Leak Test quality work instruction procedures.