Rig Freeze Protection and Winterization Standard

Purpose

A rig that goes into a freeze without protection comes out of it with a cracked pump housing, a burst hose, or a softwash tank split by ice in leftover liquid nobody drained. Each of those is a repair bill and lost days right when a shop is ramping back up, and a burst high-pressure hose is not just a repair cost, it is a line failing under working pressure with a technician holding the other end of it. This standard guarantees a rig comes out of a freeze period with every water-holding component drained, protected with a rated pump saver, or accounted for, with a written record so whoever preps the rig for spring startup knows what to flush and what to trust without guessing.

Scope

Covers seasonal winterization and extended cold-storage protection for belt-drive high-pressure pumps, softwash skids, hoses, reels, wands, and injector suction lines on this trade's 4 to 8 GPM class rigs.

Does not cover: chemical dilution ratios and tank mixing, owned by Soft Wash Skid Setup and Tank Mixing; pump and tip selection, owned by GPM and PSI Selection by Task and Nozzle Tip Selection; and a single unexpected cold night during the working season, a shorter contingency (drain what is exposed, resume normal operation next day) rather than the full seasonal shutdown this standard covers.

Roles and responsibilities

Procedure

1. Confirm the trigger and stage materials before disconnecting anything. The trigger is an overnight low forecast at or below 32 degrees F, or the rig entering extended off-season storage, whichever comes first. Stage the rated pump-saver antifreeze, spare hose caps, a storage tag, and PPE before the first fitting comes loose. Accept: trigger confirmed and materials physically staged before step 2 begins. Wrong: starting to drain the rig and discovering the antifreeze is not on hand, leaving components disassembled overnight. Stop rule: if materials are not available, the rig stays in normal rinse-only service one more working day rather than being left half-winterized. Hazard: none specific to this step; PPE staged here is what step 2 puts to use.

2. Drain and disposition the softwash chemical before anything else opens. Drain the tank fully. A dilute working batch is not carried through winter, since it degrades and can still freeze and split a poly tank; neutralize and dispose of it per the product label and local wastewater rules, never to a storm drain. Unused concentrate goes into its original, sealed, labeled container and moves to indoor storage above freezing. Accept: tank empty, dilute residue disposed per label, concentrate sealed and relocated indoors. Wrong: leaving a partial tank of dilute mix in the skid "because it will probably be fine outside." Stop rule: any tank residue that will not fully drain by gravity gets pumped or siphoned out before you proceed, since a splash of standing chemical left in a tank over winter is the single most common cause of a cracked poly tank in spring. Hazard: eye protection and the SDS-specified glove go on before this step starts, and if that does not hold, meaning chemical reaches skin or eyes during draining, flush the affected area with clean water for at least 15 minutes, the ANSI Z358.1 minimum for a corrosive splash, while someone else gets medical guidance, and the rest of the procedure waits until the exposure has been evaluated.

3. Flush every chemical line and the injector suction path with fresh water. Run plain water through the downstream or upstream injector circuit until the lines and suction tube hold no visible residue, disconnecting and rinsing the suction strainer if it does not run clear quickly. Accept: discharge runs clear with no chemical smell before flushing stops. Wrong: skipping straight to antifreeze with chemical residue still in the lines, which mixes an unknown chemistry inside a line about to be sealed for the winter. Stop rule: if the lines will not run clear after a reasonable flush, treat the residue as unresolved chemical per step 2's hazard clause rather than pushing antifreeze in on top of it. Hazard: and if the flush itself raises a chlorine or sharp odor, stop, move upwind, and do not lean in to identify it, since both chlorine and chloramine gas deaden smell at concentrations that are already harmful.

4. Push pump-saver antifreeze through the pump inlet and out the gun. Draw the rated antifreeze into the pump's inlet, run the pump briefly, and trigger the gun until discharge changes from clear to the antifreeze's own color. One pass both coats the pump's internal passages and exercises the gun's trigger valve. Accept: discharge at the gun visibly changes color and holds it for several seconds of continuous trigger pull, confirming full displacement rather than a partial slug passing through. Wrong: stopping the moment any color shows, before the change holds steady, which usually means only part of the internal path got coated. Stop rule: if color never appears after a reasonable draw, the antifreeze is not reaching the pump head, most often air-locked at the inlet; stop and check that connection rather than assuming more time fixes it. Hazard: most pump-saver antifreeze is a low-toxicity propylene-glycol product rather than the ethylene-glycol used in vehicles, but confirm the specific product's SDS and avoid prolonged skin contact regardless.

5. Drain and inspect every high-pressure hose and reel. Uncoil each hose fully, elevate one end, and let it drain by gravity; a hose that still releases water when lifted after draining has a low loop trapping it. Accept: no water releases when a drained hose is lifted and flexed. Wrong: coiling a hose for storage with a low point still holding water, which freezes, expands inside the reinforcement layer, and shows up as a pinhole burst under working pressure next season. Stop rule: a hose that will not fully drain gets stood on end or hung rather than coiled flat until it does. Hazard: none beyond routine handling; inspect for any existing abrasion or bulge while the hose is uncoiled, since this is the one time of year it gets a full-length look.

6. Locate and service the pump's low-point drain plug. Remove the plug, let trapped water clear the low point fully, then reinstall it hand-tight plus a quarter turn and confirm no seepage. Accept: plug removed, low point drains visibly, plug reinstalled and dry after a few minutes. Wrong: assuming the inlet and outlet drain covers the low point too; many pump bodies trap a separate pocket of water the main flow path never touches. Stop rule: a plug that will not turn with reasonable hand-tool force does not get forced, since continued force risks stripping the threads or cracking the housing, turning a maintenance step into a repair. Hazard: a stripped or cracked housing from a forced plug is a pressure-boundary failure waiting on next startup, so this stop rule protects the pump, not just the afternoon.

7. Service the injector suction line and its check valve. Disconnect the suction tube from the injector body, drain it, inspect the strainer and check valve for residue or cracking (see Chemical Will Not Draw Through the Injector for what a compromised check valve looks like), then reconnect the tube and confirm a snug seal with a firm tug test. Accept: strainer clear, check valve moves freely and reseats, tube reconnected and holds under the tug test. Wrong: reconnecting a tube to a check valve that does not visibly reseat, leaving anti-siphon protection unverified until spring. Stop rule: a check valve that does not reseat gets replaced now, not flagged for later, since it is the same backflow protection that keeps chemical from siphoning into a water supply during the season. Hazard: the same PPE from step 2 stays on here, since residual chemical can still sit in the check valve body even after the step 3 flush.

8. Protect the softwash skid's low-pressure delivery pump and its battery. Run the same antifreeze push described in step 4 through the skid's dedicated 12-volt pump and its own discharge line, then disconnect the battery, check its charge, and move it to above-freezing storage per its own maintenance routine rather than leaving it in the skid compartment all winter. Accept: antifreeze color visible at the skid's own discharge point, battery disconnected, charge checked, and stored above freezing. Wrong: treating the 12-volt pump as covered by the main pump's antifreeze push; they are separate systems with separate internal passages, and one does not protect the other. Stop rule: a battery reading below the level its own charge chart calls healthy gets put on a maintainer before storage, not stored flat and hoped for. Hazard: disconnect the negative terminal first when removing the battery, to reduce the chance of an accidental short across a tool bridging the terminals.

9. Tag, log, and store the unit. Attach a dated tag stating the rig was winterized, the antifreeze product used, and by whom, then move it to freeze-protected storage or, if it must stay outside, wrap the exposed pump head and battery compartment area. Accept: tag visible on the unit, unit in its assigned storage location or wrapped per this step. Wrong: a winterized rig left in the open yard with no tag, indistinguishable from one nobody has touched yet. Stop rule: a rig with no confirmed storage space does not get called finished; it gets flagged to the shop manager per the Roles table until space is assigned. Hazard: none; this step is documentation and placement.

The record this produces

The tag and the shop's rig maintenance log both carry: date, technician name, the antifreeze product and its rated protection temperature, confirmation the chemical tank was drained and its disposition (disposed or returned to storage), and any component flagged rather than completed (a seized drain plug, a failed check valve). The next person to touch this rig, most often at spring startup, reads this record to know what to flush before first use and what was already replaced, rather than re-inspecting the rig from zero.

Worked pass, with a step that failed

End-of-season shutdown on a two-unit rig: a belt-drive pump and softwash skid that had run a full season of SH-based house wash work.

Steps 1 through 5 ran clean: forecast confirmed at 28 degrees F, materials staged, tank drained with a half-gallon of dilute mix disposed per label, lines flushed clear, antifreeze pushed through with a steady color held at the gun, and all three hoses drained fully with no water on the lift test.

Step 6 failed. The pump's low-point drain plug, exposed to a season of SH-laden splash and runoff around the pump bay, had corroded enough that it would not turn with the wrench under reasonable hand-tool force. The stop rule ran as written: no additional force applied. The technician tagged the pump for the shop's mechanical repair queue rather than risking a stripped fitting or a cracked housing, and noted on the tag that steps 7 through 9 for the main pump specifically were on hold pending that repair, while the softwash skid's separate 12-volt pump (step 8, its own independent system) completed normally on schedule.

The pump went to the shop bench the following week, where the seized plug was drilled out and replaced, the low point drained and confirmed clear, and steps 6 through 9 completed and logged against the original winterization date. Forcing the plug that day would have saved perhaps twenty minutes against the bench repair; a cracked housing at spring startup would have cost the unit its first several working days instead.

References

• See related: Soft Wash Skid Setup and Tank Mixing
• See related: Downstream versus Upstream Injector Setup
• See related: Chemical Will Not Draw Through the Injector
• ANSI Z358.1 for emergency eyewash and flush duration on a corrosive chemical exposure
• Manufacturer documentation for the specific pump-saver antifreeze product's rated protection temperature and SDS